EDN Network

It’s not uncommon for a midsection to become soft and distended with advancing age. That said, when it happens to a battery, it’s potentially quite problematic.

In last week’s part 1, I took apart a third-party BLX-1 battery which had come with my Olympus (now OM System) OM-1 digital camera and which the manufacturer’s own BCX-1 charger refused to recognize as a valid recharge partner. Also recently augmenting my burgeoning gear inventory are two enthusiast-prized Olympus PEN-F Micro Four Thirds bodies (once again digital, not the film-based precursor), one in each color option offered by the manufacturer a decade ago when they were new.

Each came with a third-party BLN-1 battery (7.6 V, 1220 mAh). Supplier names differed but their physical appearances were identical, therefore suggestive of a common manufacturing source. I’ll be taking them both apart today to test my hypothesis. But why am I dissecting them at all?

Unlike the BLX-1, they seemingly still work fine, but they both arrived slightly swollen, with further distension likely after additional use and recharge cycles. The last thing I want is for an inexpensive, replaceable cell to end up permanently lodged in the battery compartment of an expensive, irreplaceable camera, so retirement and replacement was a priority for both!

Trust me when I say that all the cameras showcased in this two-part series are Micro Four Thirds models, Olympus-now-OM System to boot, is only a coincidence. I’ve had no shortage of mixed-at-best success in the past with third-party batteries for other manufacturers’ cameras, too.

Some Wasabi with your sushi?

I randomly picked the one from Wasabi Power, a common “clone” cell supplier, to disassemble first. As usual, I’ll start with some overview shots, accompanied by a 0.75′′ (19.1 mm) diameter U.S. penny for size comparison purposes. Top.

Bottom.

Four of the BLN-1 contacts—”+”, “-“, “I” and “T”—are marked the same (albeit in different ordering) as with the BLX-1. As I mentioned last time, published specifications for batteries like these are hard-to-impossible to come by, given that for various reasons the camera manufacturer doesn’t want to encourage third-party cloning.

That said, once again the functions of “+” and “-“ are likely related to the applied voltage and current involved in the fundamental cell-charging and -discharging (for camera powering) functions. “I”, typically standing for “information” or “identification”, references the interrogation initially done by both charger and camera after battery insertion and power-on, and ongoing from that point on, presumably implemented by a bidirectional single-data-pin serial communications protocol of some sort.

“T” typically references “temperature”, with the contact connected to an embedded negative temperature coefficient (NTC) thermistor or other sensor that monitors the internal cell(s) and alerts the charger to potential overheating. And this time there’s a fifth electrical contact, “S”. User research suggests that it was added in response to Japanese standards body guideline revisions that mandated a fuller shut-off of the accompanying charger after the battery reported it was “full”, thereby minimizing subsequent “vampire” power draw.

The BLX-1 battery disassembled in part 1 of this series is significantly newer in generation than the BLN-1 and presumably integrates this function along with others already supported over the “I” interface, thereby negating the ongoing need for a dedicated “S” contact.

Onward, redux. Once again, the other end is much less exciting, as are the sides.

Ongoing unexciting-dissection aspirations

And once again, a Sirens-like tempting, albeit ultrasonic-welded, seam around the battery’s circumference seems to be the most feasible pathway inside, the potential for sparks, smoke, flame, and other calamities aside. Danger, Will Robinson!

Phew!

This time, the batteries’ form factors aren’t cylindrical and plastic-covered as before, but rectangular and metallic; niftily-named prismatic, to be exact. Once again throwing caution to the wind, I pressed forward determinedly (albeit cautiously) with the disassembly.

Rubber strips again, this time tape- and paper-accompanied, to insulate the mini-PCB from the batteries’ terminals both mechanically and electrically.

Enough with the teasing; I know this is what you’re most interested in seeing, right?

The design is much more elementary than with the BLX-1 circuit board we saw in part 1. The eight-lead IC PCB-labeled as U2 is stamped as follows on top, below a cryptic company logo.

8822
E6H01

It’s another dual N-channel MOSFET. And then there’s six-lead U1 to its right, marked as follows.

CGKU

As with the BLX-1, per an earlier-referenced discussion, I’m guessing it’s a rudimentary battery-protection IC. Apparently recharge-balancing the two cells isn’t of concern in this specific case.

Speaking of which, let’s take a closer look at the markings on the two cells’ prismatic cases, which you’ve already glimpsed in prior images.

They match each other, and I suspect the last eight characters of each reference a September 2016 manufacturing date. Nearing 10 years old, I’m willing to forgive a bit of old-age swelling, no matter that it obviates any further use (that I’m comfortable taking a chance on, at least). No voltage or capacity specs; that said, I suspect they’re the relatively common 4.2 V (3.7 V nominal) variant in a serial-interconnect topology.

Testing a common-sourcing hypothesis

Now for its Newmowa-branded counterpart (is that a clever company logo, or what?), complete with scribbling on top from its prior owner (who apparently, like me, is also blessed to own a diversity of camera hardware models from various manufacturers, and needs to keep his batteries straight).

Trust me when I say that had I decided to keep the battery in service, cleaning off those contacts would have been my very next step!

Once more unto the breach, dear friends.

This time, interestingly, both cells’ cases are completely marking-free on both sides.

Although the means by which the cells are adhesively bonded both to each other and to the surrounding halves of the enclosure differ, there’s visually obvious commonality with respect to the respective mini-PCB layouts.

That said, the components are seemingly divergent from a sourcing standpoint (albeit functionally identical, at least likely). Here’s what’s atop eight-lead U2 this time:

SNE
5N20V
7H09 (don’t quote me on the accuracy of this last line; it’s pretty fuzzy)

Once again, it’s a dual N-channel power MOSFET. And six-lead IC U1 to its right? Again, don’t quote me definitively, but here’s my best shot post-cleanup with rubbing alcohol.

20DD
L607

And with that, after wrapping up all four cells (two from each of the two batteries) in insulating masking tape to ensure safe storage until after my writeup is published.

I’ll also wrap up for today. Shout out with your thoughts in the comments, please!

—Brian Dipert is the associate editor, as well as a contributing editor, at EDN.

Related Content

• Dissecting third-party camera batteries, part 1: Misbehavior
• Engineering tradeoffs: a camera case study
• Single-battery failures in multi-battery arrangements: diagnosing selective cell derangements

The post Dissecting third-party camera batteries, part 2: Swelling appeared first on EDN.

Over the last two months, we mapped out how USB-C, Power Delivery (PD), vehicle-to-load (V2L), and high common-mode transit immunity (CMTI) are reshaping the landscapes of test and measurement and electric vehicles (EVs). The next challenge is practical: how do you translate those high-level architectural requirements into a schematic that works and a PCB layout that passes?

This post delivers the essential design clues—the component choices, layout constraints, and rule-of-thumb practices—that bridge concept to copper. It’s about moving from theory to implementation, giving engineers the confidence to build USB-C and PD systems that meet compliance while surviving real-world stress.

Designing for high CMTI: Turning ratings into real layout rules

To maintain high CMTI on a real board, the isolation barrier is non-negotiable. Specialized digital isolators—either capacitive-based or magnetic-based—are engineered to withstand the brutal transient voltage spikes in the range of kV/𝜇s without corrupting USB data streams. These devices form the shield that keeps common-mode noise from bleeding across domains.

Placement is equally critical: the isolator must straddle a deliberate, wide physical gap on the PCB. That gap is a true keep-out zone; no copper traces, power planes, or ground planes are allowed to cross it. The isolator alone bridges the divide, ensuring that the high-speed USB signals remain intact even under aggressive switching events. This disciplined layout practice is what turns theoretical CMTI ratings into reliable, repeatable board-level immunity.

Figure 1 Application diagram of ISOUSB211 reveals how the isolation barrier prevents data corruption caused by ground loops and power-stage switching noise. Source: Texas Instruments

Implementing USB-C and PD controllers: The schematic clues

Moving from standard USB to USB-C with Power Delivery—and even V2L—requires dedicated silicon. At the simplest level, configuring a USB-C port hinges on the CC pins. If the design is a power sink, such as a basic test and measurement instrument, you must place 5.1 kΩ pull-down resistors (Rd) on both CC1 and CC2 pins.

Conversely, if the design is a source, pull-up resistors (Rp) are required to advertise available current. For higher-power PD or bidirectional V2L applications, engineers should resist the temptation to code the complex negotiation state machines inside a general MCU.

Instead, a standalone USB-PD controller IC is the right choice—it encapsulates the protocol logic, manages the timing, and ensures compliance, freeing the system MCU to focus on application-level tasks. This division of labor is what makes USB-C and PD designs robust and certifiable in practice.

Figure 2 This simplified block diagram of the MAX77958 IC details the USB Type-C CC detection and Power Delivery protocol implementation. Source: Analog Devices

The 90-Ω differential layout: The PCB clues

High-speed USB signaling in USB 3.x and USB4 behaves much more like RF than low-speed digital. If the layout is off, compliance failures are inevitable. The first design clue is impedance control: the D+/D– or TX/RX traces must be routed as a matched differential pair with a strict target of 90 Ω. Deviations here directly translate into eye-diagram collapse and failed certification.

The second clue is geometry for ESD protection. In harsh EV and lab environments, transient voltage suppressor (TVS) diodes must sit physically as close as possible to the USB-C connector pins. The ESD spike must be absorbed at the connector entry point—before it can travel down the trace and reach sensitive silicon. This placement discipline ensures that compliance isn’t just theoretical but survives the real-world surge events that USB-C designs inevitably face.

Figure 3 Hand-drawn illustration of an eye diagram highlights the mask keep-out zone at the center. This stylized ‘open eye’ demonstrates the compliant signal quality expected in USB 2.0 links when the differential pair achieves routing near the 90-Ω target. Source: Author

Tips from the bench: What datasheets don’t mention

While mapping out your schematic and tracking your traces, keep these three notorious real-world layout traps in mind. They are the most common culprits behind first-revision PCB failures:

• Guard the CC pins against high-voltage shorts

Inside the microscopic geometry of a USB-C receptacle, the Configuration Channel (CC) pins sit directly adjacent to the high-voltage VBUS power pins. A slightly tilted cable insertion, a worn-out connector, or a bit of metallic debris can instantly short a 20-V VBUS line straight into a CC pin. Standard 3.3-V or 5 V-MCU inputs will instantly fry.

The fix: Always specify standalone USB-PD controllers featuring integrated 24 V short-to-VBUS protection on the CC lines.

• Tame the VBUS hot-plug voltage ringing

When a user hot-plugs a live Power Delivery adapter into your board, the parasitic inductance of the USB-C cable slams into the input capacitance of your PCB. This creates an LC circuit that can ring up to twice the nominal voltage, turning a standard 20-V PD profile into a destructive 40-V spike that easily ruptures downstream buck regulators.

The fix: Anchor the VBUS entry point with a heavy-duty, high-voltage TVS diode or an over-voltage protection (OVP) eFuse paired with a minimum of 10 uF of bulk ceramic capacitance to dampen the surge.

• Ban via stubs on your 90-Ω pairs

Achieving a strict 90 Ω target impedance requires flawless trace geometry. Every time a high-speed TX/RX or D+/D- pair hops between PCB layers through a via, it hits an impedance speed bump. Worse yet, if a trace transitions from the top layer to a middle layer, the remaining unused barrel of the via hangs off the signal path like an antenna. This “via stub” creates severe RF reflections that can collapse your eye diagram entirely.

The fix: Route high-speed USB lines on a single layer whenever possible. If layer transitions are absolutely non-negotiable, limit them to a maximum of two, place adjacent ground return vias right next to them to preserve the return path, and enforce back-drilling on multi-layer boards to eliminate the stubs.

This bench-level awareness is what keeps your first spin from becoming a costly lesson in overlooked physics.

Closing 3-month power and signal loop

Month 1 and month 2 set the destination, showing how USB-C, Power Delivery, V2L, and high CMTI are reshaping test and measurement and EV platforms. Month 3 provided the map: the schematic clues, resistor choices, isolation gaps, and PCB layout rules that turn concepts into copper.

The takeaway is clear: these design rules tie the journey together, moving from vision to verified hardware. By closing the loop with practical guidance, engineers are equipped not just to understand USB-C and PD, but to implement them with confidence in real boards and systems.

Carry these power and signal rules into your next design cycle; apply the resistor networks, enforce the isolation gaps, and route those 90-Ω pairs with precision. Share your own board-level lessons with peers and keep expanding the collective toolkit that transforms ambitious USB-C and PD concepts into reliable, compliant hardware.

T. K. Hareendran is a self-taught electronics enthusiast with a strong passion for innovative circuit design and hands-on technology. He develops both experimental and practical electronic projects, documenting and sharing his work to support fellow tinkerers and learners. Beyond the workbench, he dedicates time to technical writing and hardware evaluations to contribute meaningfully to the maker community.

Related Content

• USB Keypad Reference Design
• USB Proves Ready for T&M Tasks
• Top 10 innovative USBs and peripherals
• Take off with Simplified USB Type-C Development
• The USB takeover: Why modern T&M is moving to your pocket
• A quick and practical view of USB Power Delivery (USB-PD) design

The post Component and layout rules for USB-C, PD, and CMTI appeared first on EDN.

Live wire power poles present obvious danger to wildlife, but emergency response plans for such events unfortunately seem to be inadequate.

The following screenshot image (Figure 1) shows a black bear that actually managed to climb to the top of a power utility pole. The location was along Route 56 in New Mexico. While the bear was alive at the moment this image was captured, it was later electrocuted by the power lines, which reportedly carried 7200 volts.

Figure 1 Trapped bear unfortunately ends up electrocuted and deceased.

There have been several stories about this event. A link to one of them can be found here.

The danger that live wire power poles can present to wildlife, to birds in particular, has been addressed before. Please see here.

Quite frankly, I never expected that such an animal could get itself into trouble like that, yet I recently watched a PBS nature program where a black bear was seen effortlessly climbing a tree while hunting prey.

There are stories online of similar prior incidents having taken place. Here, it was speculated that since the event happened adjacent to a roadway, the bear might have been spooked by a passing vehicle and sought refuge by climbing that pole.

Emergency response plans for such events seem to be inadequate. Since they are already known to occur, however regularly or sporadically, I would have expected proper emergency response plans to have long ago been put in place, to turn electric power off and to then safely rescue the endangered animal(s). Instead, I see very little sign of emergency preparedness.

The emergency response operator in this case gave a verbal recitation along the line of “there’s nothing they can do.” There’s nothing that bear can do either, at least not anymore.

John Dunn is an electronics consultant and a graduate of The Polytechnic Institute of Brooklyn (BSEE) and of New York University (MSEE).

Related Content

• A wing and a wire
• Why do you never see birds on high-tension power lines?
• A tale about loose cables and power lines
• Misplaced insulator proves fatal
• Underground power line feasibility

The post Bear on a power pole appeared first on EDN.

Every embedded project eventually needs to address similar challenges around how much storage should be allocated to the operating system, how much should be reserved for applications, how much capacity should be allocated for system and diagnostic logs, and whether there is enough space for future software updates.

These decisions are usually made early in development, long before the first product reaches the field.

For years, that approach served the embedded industry well. Software changed relatively slowly after deployment, applications performed clearly defined functions, and storage requirements were stable enough that engineers could make sensible decisions upfront and rarely revisit them.

Today, many teams are discovering those decisions don’t last nearly as long as they used to. Products that once received only occasional firmware updates now continue evolving throughout operational lifetimes that often exceed 15 years. The hardware stays the same, but the software keeps changing.

Moving beyond static partitions

Static storage partitioning solved an important engineering problem. Applications were isolated from one another, storage behaviour was predictable, and engineers knew exactly where critical software and data would reside. In embedded systems, that level of determinism remains valuable. Today, the challenge is that software-defined systems rarely evolve evenly.

One application may barely change throughout the life of a product. Another may double in size over several software releases. At the same time, logging requirements increase, configuration data expands, and new AI models arrive years after the original storage layout was designed.

Eventually, the symptoms become familiar. One partition starts running out of space while another still has capacity that will probably never be used. Software teams spend time optimizing storage layouts instead of developing new functionality. Hardware that still has usable flash becomes constrained because it cannot be used where it’s needed most.

Why overprovisioning isn’t a long-term answer

One obvious response is to reserve more storage during development. Many embedded platforms already include generous safety margins for exactly this reason. If engineers don’t know which applications are likely to grow over the next decade, the safest option is often to allocate additional storage to all of them. That approach reduces immediate risk, but it also leaves flash capacity permanently tied to assumptions that may never prove correct.

As software-defined products become more complex, and flash prices continue to rise, this strategy becomes increasingly difficult to justify. Industry analysts have reported significant increases in NAND and NOR flash prices over the past year, meaning every additional gigabyte contributes to higher hardware costs. As a result, overprovisioning has become a bill-of-materials (BoM) consideration.

The impact of software updates

Over-the-air (OTA) updates illustrate the problem particularly well. Reliable update strategies require storage for downloading, validating, and, if necessary, rolling back software when something goes wrong. Traditional A/B partitioning addresses this by maintaining duplicate software images so that the previous version remains available until the update has been verified. This means significant amounts of flash remain reserved for situations that occur only during the update process.

A/B partitioning remains a proven and widely adopted approach because it provides a straightforward and reliable rollback mechanism if an update fails. The trade-off is that maintaining two complete software images requires a significant amount of flash to remain reserved for the update process.

As software-defined systems become more capable, that approach can increase storage requirements, enlarge software downloads, and add to the cost and complexity of deploying updates across connected devices. With flash prices continuing to rise, many engineering teams are beginning to question whether permanently reserving that capacity remains the right trade-off for every platform.

Looking at storage differently

Rather than treating storage as a collection of permanently assigned partitions, more engineers are beginning to view it as a managed system resource. This is where the concept of a dynamic data layer becomes useful.

One of the challenges it addresses is static storage allocation. Instead of permanently assigning flash to individual applications, storage can be managed as a shared resource. Applications remain isolated through mechanisms such as subvolumes, while quotas define how much storage individual workloads may consume and reservations ensure critical functions always retain guaranteed capacity.

This allows storage to adapt as software evolves. Capacity that would otherwise remain stranded in one partition can be made available elsewhere, improving utilization without sacrificing isolation or predictability.

Rethinking OTA architectures

The data layer also creates opportunities to rethink how over-the-air updates are managed. Traditional A/B partitioning remains a robust and widely adopted approach because it provides a straightforward rollback mechanism if an update fails. However, maintaining duplicate software images permanently reserves a significant amount of flash capacity.

Snapshot-based approaches provide an alternative. Rather than storing two complete software images, the file system tracks changes at the block level so only modified data needs to be written during an update.

The pre-update snapshot provides a reliable rollback point while reducing storage overhead, download size, and update effort. As flash prices continue rising, more engineering teams are evaluating these techniques as another way to improve storage efficiency without compromising reliability.

Flexibility still requires discipline

Dynamic storage management doesn’t remove the engineering constraints embedded systems have always depended on. Deterministic behavior remains essential as critical applications still require guaranteed resources. Functional safety, reliability, and predictable recovery mechanisms continue driving architectural decisions.

The objective isn’t to make storage dynamic for its own sake but to recognize that software is no longer static in the way it was when many of today’s storage architectures were originally conceived. As systems continue to evolve throughout their operational lifetime, storage management must evolve with it.

A different role for the data layer

Storage has traditionally been viewed as supporting infrastructure. Once the partition layout was complete, attention naturally shifted to processors, applications, and communications.

Software-defined systems are changing that perspective. The data layer is becoming a more active part of system architecture because it influences how efficiently software can evolve throughout the life of a product. It affects update strategies, application growth, storage utilization, and long-term maintainability just as much as raw flash capacity.

Instead of asking whether today’s applications fit into today’s partition layout, engineers are beginning to ask whether the storage architecture itself is capable of supporting software that hasn’t yet been written. While the answer will differ from one platform to another, what seems increasingly clear is that storage can no longer be designed around the assumption that software remains static after deployment.

Embedded systems have entered an era of continuous software evolution, and the architectures beneath them need to evolve for the same reality.

Sami Kassimäki is product manager at Tuxera.

Related Content

• Embedded Basics
• 8 pillars of embedded software
• 7 tips for optimizing embedded software
• Embedded systems: The marketplace in 2028
• Can Agentic AI Solve the Embedded Software Problem?

The post Why software-defined systems require a dynamic data layer appeared first on EDN.

I like to read about research innovations even if most of them don’t represent in an advance that can be commercialized or even leveraged to boost technology in general. Sometimes, the work that the team has done demonstrates innovation, discusses ways they addressed and hopefully resolved problems, and even gives insight into areas where there are remaining barriers to overcome.

That’s the case with a research paper I came across on use of paper as a substrate of passive electronic components and interconnects. In the work, “High-Density Papertronics via Laser-Written Hydrophilicity on Hydrophobic Parchment Paper” published at ACS Applied Materials & Interfaces, researchers discuss the long path they have taken to develop their latest effort in paper electronics—dubbed “papertronics”—with the use of standard parchment paper as a substrate for passive electronic elements.

This project builds heavily on other work the team has done under Professor Seokheun “Sean” Choi of the Department of Electrical and Computer Engineering at Binghamton University’s Thomas J. Watson College of Engineering and Applied Science (New York State). They have investigated the use of paper to create fully biodegradable circuit elements such as batteries, sensors, and other components.

The papertronic devices are intended to be low cost, environmentally friendly, and suitable for applications such as single-use medical patches that power using sweat, water, or even saliva as their working fluid. While paper-based electronics of various types are being investigated in many labs, this group has done a significant amount of leading-edge work in this area with a lengthy track record.

Their previous attempts to build passive circuit elements used chromatography paper as a substrate; this paper is a specialized, high-purity cellulose material widely used as the stationary phase to separate mixtures of chemical substances, inks, or plant pigments via capillary action. Unlike everyday normal paper, which contains fillers and sizing agents that interfere with fluid movement, chromatography paper has a consistent texture, controlled thickness, and predictable capillary action, vital for accurate laboratory results.

That approach proved the concept but revealed a stubborn limitation: the wax barriers used to define circuit features blurred and spread when heated, limiting the smallest achievable features to about a millimeter. That kept circuits large—on the scale of tens of centimeters—and prevented the kind of compact, tightly packed designs needed for practical applications.

Rethinking the problem

Their new approach required a radical shift. Instead of hydrophilic chromatography paper, they switched to hydrophobic parchment paper, and using a laser to selectively create hydrophilic channels rather than wax to create hydrophobic barriers, the team inverted the entire fabrication paradigm (Figure 1).

Figure 1 By targeting the parchment paper with a laser, Professor Choi and his team removed the silicone coating to expose water-absorbing cellulose fibers. The channels then act as microscopic highways that guide water-based conductive inks to form electronic circuits. Source: Binghamton University

Note that parchment paper—also called “baking paper”—is a heat-resistant, silicone-coated paper used in cooking and baking as a non-stick, greaseproof surface; you can buy it at almost any supermarket as well as from cooking-supply sources. But there’s some potential for verbal confusion here; the research team is using silicone-based paper as the substrate rather than more-familiar “silicon.” Silicone, of course, is a synthetic rubber-like substance made by combining silicon with oxygen, carbon, and hydrogen.

They developed hybrid paperfluidic-electronic techniques that exploit parchment paper’s capillary action to wick functional materials into predefined regions, yielding components such as resistors, capacitors, inductors, and interconnects (Figure 2).

Figure 2 Conceptual illustration of wax-printed versus laser-induced papertronics. In row (a), wax-printed papertronics on hydrophilic cellulose paper highlights the multiple fabrication steps required for hydrophilic pattern formation via single-sided wax printing and thermal penetration (i) and hydrophilic patterning via asymmetric double-sided wax printing and thermal penetration (ii). In row (b), molten-wax spreading during thermal penetration inherently blurs feature boundaries and limits the achievable resolution. Laser-induced papertronics on hydrophobic parchment paper demonstrates a simplified, low-temperature fabrication workflow that enables direct hydrophilic patterning without wax spreading or high-temperature processing (i) and the realization of high-density papertronic circuits with narrow hydrophilic channels and tightly spaced insulating regions (ii). Source: ACS Publications

The result is circuit features as small as 250 micrometers wide with 300-micrometer spacing—a twofold to threefold improvement over the best wax-based methods, and small enough to fit complete filter circuits into a footprint measured in millimeters rather than centimeters.

The differences due to the inverted thinking are clear: with chromatography paper, they were fighting against molten wax spreading through the paper. With their laser approach and parchment paper, the pattern is defined by the laser spot size and stays exactly where they put it. There is no spreading, no blurring, and no uncertainty.

Critically, all of the functional inks used in the work are water-based and free of toxic metals or organic solvents. The circuits are biodegradable, breaking down in soil within weeks, and can be incinerated to ash in seconds if rapid disposal is needed. For applications that require longer operational lifetimes, a thin silicone encapsulation layer protects the devices from humidity and mechanical damage without affecting their electrical performance.

Fabrication technique

As a first step, they used Fourier-transform infrared (FTIR) spectroscopy to determine the chemical composition of the pristine parchment paper, the surface modifications induced by laser treatment, and the effect of “ink” deposition. Laser irradiation induces pronounced photothermal and photochemical modifications to the parchment paper surface, which they assessed as well.

They then used laser modification to convert selected regions into ink-guiding hydrophilic microchannels. The localized laser-induced heating modifies the surface chemistry and microstructure without requiring additional chemical coatings, fillers, or high-temperature treatments.

Using a 50-watt CO2 laser, the laser power and scan speed were systematically tuned to optimize local heating and patterning of silicone-coated parchment paper. It took a significant amount of trial and error to find the optimum power and speed pairing. With a high-power and low-scan speed, the laser overheated the substrate, burning through the hydrophilic cellulose layer and cutting the paper. At low power and high speed, the silicone coating was only partially removed or not removed at all, thus preventing proper penetration of the functional materials.

Critically, these laser-defined hydrophilic features exhibit no lateral spreading, enabling minimum feature sizes and spacings that approach the theoretical resolution limit of the optical system. This strategy enables unprecedented high-density patterning, robust pattern reproducibility, and device-scale miniaturization for a significant leap beyond what is achievable with wax printing or traditional paperfluidic techniques.

For ink used to define conductive traces and electronic components, they used poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate), known as PEDOT:PSS, with controllable viscosity and density. For many reasons, PEDOT:PSS is widely used in research projects. Using these formulations resulted in limited lateral spreading on the order of micrometers within 3D cellulose fiber network.

Then there’s performance

They constructed printed resistors, interdigitated capacitors, low-loss interconnects, and integrated low- and high-pass RC filters within a single paper layer, exhibiting predictable, tunable electrical behavior consistent with circuit theory. The conductive lines have a width of ∼250 μm and a line spacing of ∼300 μm, corresponding to a PCB pitch of ∼550 μm.

The team demonstrated the platform’s versatility by fabricating a complete set of electronic components on paper: resistors whose resistance can be tuned over three orders of magnitude simply by adjusting the ink formulation; interconnects with sheet resistance as low as approximately one ohm per square, rivaling rigid electronic systems; capacitors tunable from microfarads to millifarads; and fully functional low-pass and high-pass RC filters whose frequency response closely matches theoretical predictions.

For example, the resistor values were independently controlled through three parameters: ink concentration, dimethyl sulfoxide (DMSO) content, and resistive line length. The laser-defined hydrophilic channels acted as deterministic templates that confined conductive inks, while the surrounding silicone-coated parchment remained hydrophobic and electrically insulating. This spatial confinement decoupled electrical tuning from uncontrolled ink spreading and penetration, enabling predictable and reproducible resistor geometries.

Note that DMSO is a poor electrical conductor on its own because it’s a molecular liquid without free ions or electrons. However, when ionic compounds like salts or acids are dissolved in it, it acts as a polar aprotic solvent that readily dissociates those ions, allowing the resulting solution to conduct electricity.

The laser-defined hydrophilic channels act as templates that confine conductive inks, while the surrounding silicone-coated parchment remains hydrophobic and electrically insulating. This confinement decouples electrical tuning from uncontrolled ink spreading and penetration, enabling predictable and reproducible resistor geometries.

Overall, the resistance of the paper-based resistors can be continuously tuned over a broad range from approximately tens of ohms to several kilohms (Figure 3).

Figure 3 For paper-based resistors, schematic illustrates how laser-defined paper resistors are tuned by three independent parameters: ink concentration, DMSO addition, and resistor geometry (a). Optical microscopy image (i) and SEM image of the A–A′ cross-section of a representative resistor (ii) show that PEDOT:PSS is precisely confined within the laser-treated hydrophilic region and surrounded by untreated hydrophobic parchment paper (b). Measured resistance of resistors is fabricated with varying ink volumes, where PEDOT:PSS was systematically diluted with deionized water to concentrations of 100%, 75%, and 50%, plotted as a function of resistor length (c). Resistance as a function of DMSO concentration in the PEDOT:PSS matrix is shown with weight percentages ranging from 2% to 20%, plotted as a function of resistor length (d). Data in (c) and (d) represent mean ± standard error from at least 10 independent measurements per data point. Solid lines are least-squares linear fits. Source: ACS Publications

For capacitors, conductive PEDOT:PSS electrodes were precisely patterned into interdigitated fingers using laser-induced hydrophilic channels, while the surrounding silicone-coated parchment remains hydrophobic and electrically insulating. The capacitance increases monotonically with the number of interdigitated fingers, reflecting the enlarged effective electrode surface area and reduced ionic diffusion distance inherent to the interdigitated geometry.

They achieved capacitance values spanning from the low microfarad regime to over 1.2 millifarads (Figure 4). The ability to modulate capacitance over nearly three orders of magnitude using only electrolyte composition and electrode geometry demonstrated the exceptional tunability of this capacitor platform.

Figure 4 For paper-based capacitors, schematic illustrates a laser-defined interdigitated capacitor fabricated on hydrophobic parchment paper (a). Optical microscopy image (i) and SEM image of the A–A′ cross-section of a representative capacitor (ii) show that conductive PEDOT:PSS ink is precisely confined within the laser-treated hydrophilic regions to form interdigitated electrode fingers, while the surrounding parchment paper remains hydrophobic and electrically insulating (b). Measured capacitance of capacitors fabricated with varying H3PO4 concentrations in the PVA gel electrolyte is plotted as a function of electrode finger number (c). Galvanostatic charge–discharge (GCD) curves are measured at a constant current of 2 μA after different numbers of charge–discharge cycles (d). Capacitance retention as a function of cycling number demonstrates the cycling stability of the paper-based capacitor (e). Source: ACS Publications

Interconnects and filters

The capillary scheme was also used to create interconnects, leading to what can be considered as “integrated circuits”. To demonstrate circuit-level integration, they fabricated first-order low-pass and high-pass RC filters.

All of the hydrophilic regions were defined in a single laser step, and components were sequentially deposited using paper stencils. The first-order low-pass RC filter composed of a series resistor and a shunt capacitor (Figure 5).

Figure 5 For paper-based RC filters fabricated on parchment paper, part A shows a low-pass RC filter: schematic illustration (a), circuit diagram (b), and photograph of the low-pass filter fabricated on parchment paper (c). Frequency-dependent gain plots for low-pass filters with different resistance values (46 Ω, 95 Ω, and 150 Ω) demonstrate low-pass cutoff behavior (d). Part B shows a high-pass RC filter: schematic illustration (a), circuit diagram (b), and photograph of the high-pass filter fabricated on parchment paper (c). Frequency-dependent gain plots for high-pass filters with different resistance values (15 Ω, 46 Ω, and 95 Ω) demonstrate high-pass cutoff behavior (d). Source: ACS Publications

Since the resistor, capacitor electrodes, and interconnects required different ink formulations and additives, each printing step is performed using a dedicated paper stencil. Despite this, the overall process remains low-temperature and highly reproducible.

They also assessed environmental aspects and biodegradability. Although parchment paper incorporates a thin silicone coating to give it hydrophobicity, the substrate is predominantly cellulose-based with the silicone layer accounting for only a minor fraction of the total material volume (typically <2 μm in thickness).

As a result, degradation is governed primarily by the underlying cellulose fiber network. The silicone coating, while more persistent in natural environments, is widely recognized as biocompatible and chemically inert, and its limited mass minimizes its environmental burden.

But no transistors, at least not yet

The team’s paper is quite detailed with respect to the underlying materials science, elemental physics and chemistry, and other considerations. They also acknowledge a significant shortcoming; thus far, no active devices such as transistors.

I applaud their willingness to switch from one type of paper and fabrication to a very different scheme when the first approach reached a dead end. It takes an open mind to start over and re-assess what is working and what is not.

Based on their track record with various embodiments of papertronic devices, I wouldn’t be surprised if they get the needed funding to further pursue their work toward papertronic transistors using what they have learned thus far. That would certainly be impressive.

Bill Schweber is a degreed senior EE who has written three textbooks, hundreds of technical articles, opinion columns, and product features. Prior to becoming an author and editor, he spent his entire hands-on career on the analog side by working on power supplies, sensors, signal conditioning, and wired and wireless communication links. His work experience includes many years at Analog Devices in applications and marketing.

Related Content

• Is Graphene the Next Silicon?
• “Wideband” still elusive in electronic noses
• Can we get “printed” circuit boards which really are printed?
• How SAW devices, wireless ASICs tackle torque-sensing challenge

The post Paper-based passives show impact of re-thinking substrate appeared first on EDN.

Attempted prohibitions of foreign-sourced products based solely on theoretical claims, absent irrefutable supportive factual evidence, only invites domestic-supplier favoritism accusations.

Last year I went on a “bit” of a(nother) drone-buying binge. Following up on the first-generation DJI Mavic Air I’d bought in mid-2021.

And the two DJI Mini 3 Pro drones (once again, accompanied by an abundance of accessories) I’d acquired in mid-2024.

I got two more gently-used drone gear sets from Lensrentals in 2025; the computer vision-based collision avoidance surround-enhanced and LiDAR-augmented Mini 4 Pro.

Followed by a first-person view (FPV) “cinewhoop” drone, the first-generation DJI Avata.

And in-between those two acquisitions, chronologically speaking, was the first-generation DJI Neo I bought from Amazon in a three-battery kit configuration.

What was behind this seeming conspicuous consumption behavior? Curiosity, for one thing; FPV operation, for example, was something that had captured my interest ever since I first saw the famous “Right Up our Alley” video more than a half-decade ago.

An essentially autonomous (albeit optionally still traditionally controllable) drone with a starting price just slightly more than $100 was also intriguing, both personally and professionally.

And I’ve already mentioned the feature set enhancements the Mini 4 Pro offers over its Mini 3 Pro precursor, which were insufficient temptation in 2024 but which I succumbed to a year later once I came across a sufficiently discounted like-new version.

Heavy is the hand that holds the crown

That all said, scarcity fears were admittedly also a factor, driven by seemingly inevitable pending government regulation-driven bans on DJI drones, along with other image capture-capable devices from the company, such as vlogging and action cameras. Back in mid-2024, the U.S. House of Representatives had passed legislation introduced a year-plus earlier, which banned further sales of drones from DJI and other suppliers deemed too friendly to the Chinese Communist Party, despite a longstanding absence of any tangible (public, at least) evidence supportive of this stance.

Although, subsequently introduced in the U.S. Senate, it was never voted on, therefore not becoming a law. But that outcome was a false solace; U.S. Customs began blocking imports of DJI drones and other products that same October.

By mid-2025, U.S. retailer inventories of existing DJI devices had notably evaporated. And the company didn’t even bother formally introducing newer drones such as the Mavic 4 Pro, Mini 5 Pro, Neo 2, Avata 360 and Lito 1/X1 in the United States. That all said, as it turns out, the final ruling from the U.S. Federal Communications Committee (FCC), announced two days before Christmas 2025 (believe it or not), admittedly wasn’t as egregious as initially feared (although a further retroactive-recall carve-out remains in place).

Imports of future-announced drones, including future generations of existing drone lines, were prohibited. But existing drones were once again green-lit for shipment and sale, including ongoing firmware updates (for at least a few more years) and broader usage (subject to existing FAA regulations) for products already in customer hands. Which is why you can now find the Mavic 4 Pro, Mini 5 Pro, Neo 2, and Avata 360 for sale at some U.S. retailers.

But only some. Notably, DJI not only subsequently sued the FCC but doesn’t include its latest products on the U.S. version of its online store. Even legacy drones remain unavailable; they’re “out of stock”.

Equally disruptive, the company won’t honor warranty claims coming from U.S. residents for products purchased through third parties. And speaking of which, some large U.S. retailers, such as Amazon (but not others such as Adorama and B&H Photo Video, interestingly), are continuing to decline to inventory and sell the latest DJI drones themselves, although they’ll act as marketplaces and shippers for others.

Meanwhile, DJI is reportedly rebranding its products as coming from “shell” companies to dodge restrictions (at least temporarily). You can still buy anything you want, including supposed banned newer drones such as the Lito 1 and X1, from outside-U.S. sellers via eBay, Mercari, and other online marketplaces. And if you know anyone in Canada or Mexico, or briefly pop across the border or more broadly travel internationally yourself, you can also get your unconstrained DJI “fix” that way. So how much of a ban on new drones is it, really?

What happened to free markets?

Am I suggesting that the U.S. government’s actions are completely misguided? Not at all. Obviously, the People’s Republic of China is a leading adversary, with a vested interest in collecting any and all surveillance information, whether audio, visual, and/or otherwise. And ironically, effective May 1, 2026, China itself has banned all drone sales and rentals in Beijing, the capital, along with restrictions on the broader storage of drones and drone components within the city. So, for one of its leading companies to complain about sales and usage restrictions elsewhere in the world is a “bit” of a “doth protest too much” situation, methinks.

That said, as I’ve mentioned previously, DJI’s longstanding greater-than-90% market share in consumer drones also can’t (or at least shouldn’t) be overlooked, as it reflects both the sizeable installed base and ongoing customer preference. Notable, as well, is the fact that other drone companies such as Skydio have already withdrawn from the broad market, focusing solely on enterprise opportunities going forward.

So, even if the U.S. government had hoped to use a DJI ban to boost the fortunes of alternative domestic suppliers, that supply doesn’t currently exist. And regarding the security angle, while I get it (though I’d still welcome indisputable proof of it) for gear that can directly live-stream audio and images using DJI’s own applications, I remain baffled as to why such bans extend to devices that aren’t directly Internet-connectable, especially those (such as gimbals) with no native multimedia data-capture capabilities.

Anyway, it’s not just consumers like me that’ll be affected. Here, off the top of my head and in no particular order save for how they streamed out of my noggin, are examples of business and civic entities already making notable use of drones, with broader near-term expansion planned.

• Restaurants and chains
• Food-and-other delivery services
• Law enforcement, including border patrol
• Fire spotters and fighters
• Ranchers and farmers
• Medical facilities
• Utility companies
• Filmmakers
• Researchers of all sorts
• Musicians and other performers

To wit, here’s just one recent case study from just a few miles to the east of me:

Are many of them currently using DJI-branded equipment? You bet. Can at least some of them switch to non-DJI drones in the future, assuming sufficient supply exists? I suppose. But at what cost? Not insignificant. And can all, or even many, afford the incremental investment? Doubtful.

Thereby likely explaining, at least in part, why what was initially seen as a planned full-stop ban ended up scaled back to a going-forward prohibition…but still…consider, for example, repair and replacement-parts availability impacts, along with aforementioned warranty-coverage issues.

Other conceptually similar, more recent actions by various U.S. government entities involve restrictions on routers and cellular hotspots, along with some (but not all) connected vehicles, solar inverters and robots of all sorts…but this writeup is already running long, so I’ll save those for another day. For now, I welcome reader perspectives in the comments on the issues I’ve raised here!

—Brian Dipert is the associate editor, as well as a contributing editor, at EDN.

Related Content

• Oh little drone, how you have grown…
• Diagnosing and resuscitating a set of DJI drone batteries
• Drone regulation and electronic augmentation
• 2025: A technology forecast for the year ahead
• The (more) modern drone: Which one(s) do I now own?
• Aftermarket drone remote ID: Let’s see what’s inside thee

The post Drone bans harm customers and don’t actually close the door appeared first on EDN.

Montage Technology has introduced the M88MX6852, a CXL 3.2 Memory eXpander Controller (MXC) chip for AI infrastructure and data center applications. The device has entered trial production and has been integrated into next-generation CXL products developed by memory module manufacturers including Samsung and SK hynix.  It is also designed for interoperability with Intel Xeon and AMD EPYC server platforms.

By converting host CXL memory requests into DDR commands in real time, the M88MX6852 manages data exchange between the host processor and DDR5 memory. It supports multiple CXL memory expansion form factors, including PCIe AIC cards and EDSFF modules, enabling memory expansion, sharing, pooling, and tiering.

The M88MX6852 integrates a CXL controller, dual DDR5-8000 controllers, two RISC-V processor subsystems, and an on-chip PVT sensor. Its CXL controller complies with the CXL 3.2 specification, including CXL.mem and CXL.io protocols, as well as CXL 1.1 and CXL 2.0. Based on a PCIe 6.2 interface, it achieves data rates up to 64 GT/s over eight lanes.

Montage Technology provides an SDK along with analysis and testing tools to support product development, system validation, and production ramp.

M88MX6852 product page

Montage Technology 

The post CXL controller scales server memory appeared first on EDN.

Innodisk’s DDR5 Multiplexed Rank DIMM (MRDIMM) uses a multiplexed registering clock driver and a multiplexed data buffer to achieve data rates up to 12,800 MT/s. By enabling simultaneous access to two ranks, the memory module increases bandwidth by 60% compared to conventional DDR5-8000 registered DIMMs (RDIMMs). The architecture reduces memory controller load and lowers latency, improving performance for AI model training, LLM inference, cloud computing, and robotic automation.

Designed to fit standard 287-pin DDR5 RDIMM slots, the Innodisk DDR5-12800 MRDIMM simplifies system upgrades. Built-in eFuse and TVS safeguard against power surges, while the integrated multiplexed registering clock driver and data buffer support stable high-speed data transmission. The company says the module’s energy-efficient design minimizes power consumption, supporting the sustainability goals of modern data centers.

The DDR5-12800 MRDIMM will be available in Q4 2026 with capacities ranging from 32 GB to 128 GB.

Innodisk

The post MRDIMM enables higher DDR5 bandwidth appeared first on EDN.

Entry-level MCUs in Toshiba’s TXZ+ Series M4L Group integrate dedicated hardware and security functions for single-motor control applications. The devices feature an 80-MHz Arm Cortex-M4 core with an FPU and target home appliances, consumer products, industrial equipment, and factory automation systems.

Integrated motor control hardware includes a vector engine, programmable PWM motor control, and encoder input circuitry for motor position and speed detection. Offloading these functions to dedicated hardware reduces CPU load, allowing the MCUs to execute precise single-motor control more efficiently.

Built-in security functions help protect systems against unauthorized access and program tampering. Integrated chip protection, secure access memory, and non-rewritable flash protection safeguard firmware and system integrity. The MCUs provide 128 KB or 256 KB of code flash, 64 KB of data flash, and 32 KB of SRAM. In the 256-KB devices, the code flash is organized into two 128-KB banks, allowing one bank to execute code while the other is rewritten for firmware updates without interrupting system operation.

The TXZ+ Series M4L Group of MCUs are now in mass production.

TXZ+ M4L product page 

Toshiba Electronic Devices & Storage 

The post MCUs streamline single-motor control appeared first on EDN.

Renesas announced its third-generation DDR5 Multiplexed Rank DIMM (MRDIMM) chipset, delivering server-class speeds of up to 16,000 MT/s. The memory interface components, including the RRG5013 multiplexed registering clock driver and the RRG5103 multiplexed data buffer, are designed to meet the high memory bandwidth requirements of AI data centers, cloud infrastructure, and accelerated computing workloads.

Renesas says the Gen 3 MRDIMM chipset achieves 25% higher bandwidth than its second-generation devices while preserving standard DIMM form factors and system compatibility within existing DDR5 infrastructure. Gen 3 also introduces Device Equalization Self-Train Mode (DESTM) Quality Indication Status to improve system visibility and robustness. This feature enables users to fine-tune timing and receiver equalization training to maximize signal margins.

Renesas is working with leading CPU and platform partners to enable MRDIMM Gen 3 adoption in future server platforms. The RRG5013 and RRG5103 are sampling to select customers, including all major DRAM suppliers. Production availability is expected in the second half of 2027.

More information about Renesas’ DDR5 memory interface devices is available on the company’s DDR5 Solutions page.

Renesas Electronics 

The post DDR5 MRDIMM chipset boosts server bandwidth appeared first on EDN.

Two battery monitoring ICs (BMICs) from Nuvoton, the KA49703A and KA49713A, are designed for battery backup units used in AI servers and energy storage systems. They can monitor up to 16 lithium-ion cells, while daisy-chain communication enables up to 55 BMICs to be connected in series using a single MCU. This configuration minimizes wiring, ensures robust communication, and reduces the need for additional MCUs and isolation components.

Both devices support battery stack voltages from 12.5 V to 76.8 V. They measure individual cell voltages with a maximum error of ±2.9 mV. The KA49703A and KA49713A provide alarm outputs for overcharge, overdischarge, and abnormal high- or low-temperature conditions. Additionally, the KA49713A includes a dedicated transportation and storage mode that reduces shutdown current to less than 0.1 µA to minimize battery self-discharge.

The BMICs are supplied in 7×7-mm QFP-48 packages. Samples are available now, with mass-production shipments scheduled to begin in September 2026.

KA49703A product page 

KA49713A product page

Nuvoton Technology 

The post BMICs enable scalable battery monitoring appeared first on EDN.

Minimal circuit converts input frequency to a precision current source that also accommodates grounded inputs.

I recently had the opportunity to share a design for frequency to current loop conversion using the versatile (if somewhat ancient) LM29x7 series. Taking shameless advantage of the flexibility of these legacy devices, that minimalist design made do with just nine paltry passive parts.  Figure 1 shows its (nearly painful) simplicity (so simple it almost Hz).

Wow the engineering world with your unique design: Design Ideas Submission Guide

Figure 1 In this circuit, the LM2917 needs no added actives to make a frequency to 4-20mA current sink converter.

However, it was pointed out in the comments (thanks, RJ!) that its current sink output may not be compatible with some industrial control and monitoring hardware.  So here comes Figure 2 with a frequently friendlier current source output.

Figure 2 Four frugal extra external parts (bringing the total to 13) convert Figure 1 into a flexible current source that’s useful if the load is grounded.

Converting Figure 1’s converter from current sink to current source begins with tying pin 6 to the +24v rail.  This lets the internal voltage shunt reference Z1 float the internal “ground” reference pin 8 at 16.4v instead of at zero.  R5 provides the necessary bias current (just as it does in Figure 1), and C4 gives us some noise-bypassing insurance.  Adding cascode Q1 completes the conversion.

Although U1’s spec’d linearity and temperature coefficient are good, its initial tolerances aren’t so great. Therefore some post-assembly final calibration is unavoidable, which necessitates R1’s (4mA zero) and R2’s (20mA full-scale 5kHz) tweakability.  If you do the adjustments in the right order (first R1, then R2), they won’t interact, and calibration can be completed in s single pass.

An additional helping of flexibility comes from the fact that, if your application doesn’t need or want a 4mA baseline current, just omit R3.  Then adjust R2 normally for a top end of 20mA.  That’ll give 0-20mA with no other mods required.

References

1. https://www.ti.com/lit/an/sboa574/sboa574.pdf

Stephen Woodward‘s relationship with EDN’s DI column goes back quite a long way. Over 200 submissions have been accepted since his first contribution back in 1974.  They have included best Design Idea of the year in 1974 and 2001.

Related Content

• Painlessly convert Hz to 4-20mA current loop
• 4mA-20mA to 0mA-20mA converter’s current mirror drives grounded load
• Transistor and FVCs make linear anemometer

The post Hz to 4-20mA or 0-20mA current source is compatible with grounded loads appeared first on EDN.

During a severe sandstorm, a transport aircraft attempts to land at a remote forward operating location. Visibility is nearly zero, forcing the crew to rely on navigation, communications, and landing-assistance systems. If the aircraft were to lose its GNSS signal, local timing sources would drift. Even a few microseconds of drift could cause these systems to lose synchronization.

This can cause communication disruptions, impacts to radar and ranging systems, higher inertial navigation error, and ultimately reduce the accuracy of information displayed to the pilot. Lives and the mission could be at stake. In this scenario, the fallout would not stem from a hardware failure or cyberattack, but from a small timing error.

Take, for instance, MicroPNT GDO-1000, a GNSS-disciplined oscillator (GNSS-DO) module from VIAVI, a supplier of test and measurement, optical, and position, navigation and timing (PNT) technologies. The module, built for situations mentioned above, features MEMS-based Endura Epoch or Elite X oscillators to deliver microsecond-class, 24-hour holdover in a tiny package.

The Viavi µPNT GDO-1000 module nears atomic-clock timing holdover precision, but with a low size, weight, power and cost (SWAP-C) profile—in a footprint the size of a postage stamp. The solution provides greater flexibility to keep networks synchronized, sensors aligned, and mission systems operating with confidence across air, land, sea, space, and cyber domains—even in extreme environments.

What is a GNSS-DO?

GNSS signals can be vulnerable to jamming or spoofing. Signals can be interrupted in urban or geographic canyons and subject to outages. A GNSS-DO combines a local precision oscillator with timing from GNSS to provide accurate and resilient timing required by modern defense systems. Typically, GNSS-DOs are comprised of the following:

• GNSS receiver
• High-stability local oscillator (crystal, MEMS TCXO or OCXO, or an atomic clock)
• Disciplining algorithm (servo loop)
• 1 pulse per second (PPS) input and a 1 PPS and 10 MHz output

Under normal operating conditions, the GNSS receiver serves as the primary timing reference for the GNSS-DO, providing output signals, such as 1 PPS and 10 MHz synchronized to the GNSS 1 PPS rising edge. During this phase, GNSS-DO continuously learns and characterizes the drift behavior of the local oscillator relative to the GNSS reference.

If GNSS signals become degraded, jammed or denied, GNSS-DO seamlessly transitions to the local oscillator as the timing source. Leveraging this learned behavior, the system actively compensates its outputs to maintain accurate time alignment.

This unique combination of long-term accuracy and short-term stability makes GNSS-DO a critical enabler for military communications, radar systems, electronic defense platforms, sensor fusion networks, and autonomous systems—where precise timing is essential for mission success and operational continuity.

Choosing an oscillator with the right stuff

Drift can be caused by temperature fluctuations, vibration, mechanical stress, power supply variations, and long-term aging effects. Left unchecked, drift accumulates over time, degrading synchronization accuracy and potentially impacting system performance.

The role of GNSS-DO is to continuously correct these errors when a reference signal is available and minimize their impact when it’s not. The better the oscillator’s inherent stability, the longer and more accurately the system can maintain synchronization during a GNSS outage.

This is how the different types of oscillators compare:

• CSACs

Chip-scale atomic clocks (CSACs) offer great stability and the longest holdover performance, making them the benchmark for resilience in GNSS-denied environments. However, these advantages come with trade-offs in size, weight, cost, and procurement lead times that can limit their practicality for many deployed systems.

• Crystal TCXOs and OCXOs

Traditional crystal-based TCXOs and OCXOs provide lower-cost alternatives and are widely used across communications, aerospace, and defense applications. While they can deliver strong timing performance, quartz is very susceptible to shock, vibration and mechanical stress, causing them to crack, break, or severely degrade performance. This makes them less suitable for increasingly rugged and mobile platforms.

• MEMS TCXOs and OCXOs

Micro-electro-mechanical systems (MEMS)-based TCXOs and OCXOs are emerging as a viable solution. They provide robust resistance to vibration, shock, and environmental stress while significantly reducing size and power consumption. In many cases, MEMS OCXOs offer near atomic-level frequency stability over temperature and occupy 75x less volume. This combination enables system designers to achieve precise timing and extended holdover without the SWAP-C penalties.

Figure 1 MEMS OCXOs can outperform the alternatives for SWaP in critical military defense applications. Source: SiTime

About GDO-1000 module

The µPNT GDO-1000 module features dual-frequency L1/L5 GNSS reception with microsecond-class, 24-hour holdover, enabling highly accurate timing even in degraded or contested conditions. “Its holdover performance approaches what customers expect from atomic-class clocks, in a module that fits on a standard M.2 slot and draws approximately half a watt,” said Doug Russell, senior VP and GM for aerospace and defense at VIAVI.

Figure 2 The VIAVI µPNT GDO-1000 module featuring an advanced MEMS oscillator has dual frequency L1/L5 GNSS reception and microsecond-class 24-hour holdover and draws less than half a watt of power. Source: SiTime

Moreover, it integrates directly into modern compute platforms, time appliance cards, and embedded systems without custom mechanical design.

The module performance is enhanced by patented AI and ML algorithms which model and compensate for oscillator behavior across varying environmental conditions. At its core, MEMS oscillators provide improved thermal stability across the full military temperature range compared with traditional quartz OCXOs, while maintaining phase noise and Allan Deviation performance under vibration and shock.

The system also accepts an external 1 PPS input, allowing discipline from M-Code GPS, alternative navigation sources, or other external references without hardware modification. Despite its miniature size, it supports multiple 1 PPS and low-phase-noise 10 MHz coaxial inputs and outputs, providing flexible integration across complex systems.

Modern precision timing solutions such as the advanced OCXO platform and high-performance Super-TCXO architectures are designed to directly address the combined challenges of SWaP constraints and oscillator drift and loss of reference time in GNSS-degraded environments. By improving intrinsic frequency stability, reducing phase noise, and minimizing long-term aging effects, the devices help maintain more accurate local timekeeping when external references are unavailable.

As defense systems evolve from standalone platforms into interconnected networks of sensors, communications systems, and autonomous assets, timing is becoming as fundamental to system design as power and memory management. Precision timing enables everything from PNT to secure communications, sensor fusion, and synchronized operations across distributed missions.

The future belongs to timing solutions that deliver precision, resilience, and performance while minimizing SWaP and system complexity.

Tyler Hohmann is business development director for aerospace and defense at SiTime, where he leads strategy and execution across prime contractors, startups, and sub-system manufacturers to advance precision timing adoption in mission-critical systems. Prior to SiTime, he was VP of sales and marketing and co-founder of Safran Federal Systems.

Related Content

• MEMS Resonators Drive Advanced Timing Solutions
• MEMS timing disrupts quartz in modern automotive
• The top 6 reasons to use silicon MEMS timing solutions
• How to use MEMS OCXOs to overcome timing challenges
• GNSS Receiver Frequency Reference for Successful Satellite Navigation

The post GNSS oscillator with 24-hour holdover in a postage-stamp size appeared first on EDN.

Front-panel push button controls can conveniently adjust a PCB-mounted internal potentiometer’s resistance.

Digital potentiometers in conjunction with MCUs find common use in analog circuits. The processor can adjust the gain of an amplifier, frequency of an oscillator, time delays, etc. using a digital potentiometer whose resistance is controlled via software. However, plenty of MCU-less applications also exist; in some cases, they implement conventional potentiometers mounted in system front panels for manual resistance control purposes.

Wow the engineering world with your unique design: Design Ideas Submission Guide

Imagine the convenience, however, if two push buttons are alternatively provided in the front panel to increase or decrease the resistance of each potentiometer, which can then be alternatively located on the PCB within the system. Such an approach may, for example, be a welcome capability in audio, high frequency, automotive, and other applications. This is exactly what the circuit shown in Figure 1 does.

Figure 1 Each press of the “INC” (increment) push button increases resistance by one step. Similarly, each “DEC” (decrement) push button press decreases resistance by one step. The power supply and ground pins of the various ICs are not shown in this schematic.

This simple design uses only two ICs to adjust the digital potentiometer, shown here as an example 128-step 10K ohm AD5220BN10 (PDF) and labeled U3. A more complex implementation can include multiple versions of the circuit, each based on a different-value potentiometer, and each separately managed via unique control of the CS, CLK and U/D pins.

U3 pins A and B are resistor ends, and W is the “wiper”. How does the circuit work? When you momentarily push the “INC” (increment) push button, a pulse is generated which sets flipflop U2A. Its Q output is connected to the U/D pin of the digital potentiometer. Hence U3 is set to the “up” tap direction and the wiper advances by one position.

For every subsequent “INC” push button press, the wiper further advances by one step. Similarly, when you momentarily push the “DEC” (decrement) push button, flipflop U2A is reset, causing U3 to subsequently reverse course and adjust resistance in the “down” direction. Additional “INC” push button presses further decrease the wiper, by one step each time.

And how can you test the circuit? Connect U3 pin A1 to a 5V supply and B1 to ground. Now connect a digital voltmeter to wiper W1. If you press the “INC” push button, the voltage should increase, and if you push the “DEC” push button, the voltage will decrease, if the circuit is functioning correctly. The following video shows a simulation of the circuit, complete with my narration.

Jayapal Ramalingam has over three decades of experience in designing electronics systems for power & process industries and is presently a freelance automation consultant.

Related Content

• Reducing error of digital potentiometers
• Synthesize precision Dpot resistances that aren’t in the catalog
• Synthesize precision bipolar Dpot rheostats
• Keep Dpot pseudologarithmic gain control on a leash
• Dpot pseudolog + log lookup table = actual logarithmic gain

The post Push to increase, decrease a digital potentiometer appeared first on EDN.

Radar, communications, and sensing systems increasingly rely on phased array antennas to achieve agile, precise beam steering without mechanical motion. As bandwidths widen to support higher data rates and better resolution, traditional phase-shifter-based architectures reach their limits, particularly due to beam squint and degraded performance at band edges.

True time delay (TTD) techniques, implemented using time delay units (TDUs), address these challenges by providing frequency-independent delay across the array, enabling accurate wideband beamforming in advanced active electronically scanned arrays (AESAs).

Phased array antenna fundamentals: AESA architecture and electronic beam steering

Phased arrays use multiple antenna elements arranged in uniform linear arrays (ULAs) or uniform rectangular arrays (URAs), with each element driven by a controlled phase or time delay. By adjusting these controls, the array forms narrow beams in desired directions and suppresses unwanted directions, eliminating the need for mechanical steering.

In AESA architectures, each element—or small group of elements—typically has its own transmit/receive (T/R) module, enabling multi-beam and multi-frequency operation for radar, satellite links, and advanced wireless systems.

Figure 1 Simplified phased array antenna features multiple elements with controllable phase or time delay, enabling electronic beam steering without mechanical motion. Source: Qorvo

Phased array performance may be summarized by two system-level figures of merit. Equivalent isotropically radiated power (EIRP) is expressed in dBm (referenced to 1 mW) or dBW (referenced to 1 W) and equals transmit power plus antenna gain (in dBi), assuming no cable or connector losses.

Gain-to-noise-temperature ratio (G/T) measures receive sensitivity by comparing antenna gain to system noise temperature; higher G/T values correspond to better detection and signal quality, especially important for satellite and deep-space links.

Wideband beam squint: Why phase shifters fail in high-bandwidth phased arrays

Wider instantaneous bandwidths have benefits: operation over multiple channels or bands, improved range resolution in radar, and higher data rates in communications. However, wideband operation exposes a key limitation of pure phase-shifter-based beamforming: the phase shift needed for a given steering angle depends on frequency, so a single-phase setting at the center frequency does not steer all frequencies to the same angle.

This misalignment creates beam squint, where the main beam moves with frequency across the band. At the center frequency, the beam points at the desired angle, but at the band edges, it becomes under-steered or over-steered, redistributing gain and degrading EIRP and G/T in the intended direction.

Figure 2 Illustration of beam squint in a phased array: a single-phase setting at the center frequency steers the beam correctly at F0, but under‑steers at Fmax and over‑steers at Fmin. Source: Qorvo

Why beam squint occurs for wider-band systems is illustrated in Figure 3. Beam steering using phase shifts per element attempts to ensure that energy at each element in the array arrives at the same phase for coherent summation in the beamforming network. When the beam is steered off-boresight (θ > 0), some energy arrives at one edge of the array before it arrives at the opposite edge; the extra path length is N * d * sin θ, where N is the number of elements across the array, θ is the beam steering angle, and d is the element spacing.

Figure 3 Path‑length difference in an off‑boresight phased array, showing how the extra distance N * d * sin θ at the farthest element translates into a frequency‑dependent phase shift requirement and leads to beam squint when only fixed phase shifters are used. Source: Qorvo

Dividing this longer path length by the wavelength at F0 and multiplying by 360 degrees gives the phase shift that must be applied at the farthest element. At Fmax the wavelength is shorter, so the required phase shift is larger; at Fmin the wavelength is longer, so the required phase shift is smaller, which is why a single phase shift per element at F0 leads to under‑steering at Fmax and over‑steering at Fmin.

In high-gain, narrow-beam arrays, even modest squint can cause large link-budget penalties at the band edges, while lower-gain, wide-beam arrays are more tolerant of the same angular movement.

Whether an array needs true time delay depends on the relationship between beam squint and beamwidth. Smaller arrays with broader beams can often accept the squint induced by phase-only steering, whereas large arrays with narrow beams and wide bandwidths require TTD to maintain beam pointing and gain across the full band. Design factors such as array size, element spacing, scan angle, and center frequency all feed into this assessment, with wide scan angles and high frequencies typically increasing sensitivity to timing errors.

Figure 4 Example gain patterns for the same beam movement in high‑gain, narrow‑beam and low‑gain, wide‑beam antennas, showing how beam squint produces much larger gain loss at the band edges in high‑gain arrays and necessitates the use of true time delay. Source: Qorvo

True time delay vs phase shifters: Performance comparison for wideband arrays

Traditional phase shifters implement a fixed insertion phase at a given frequency, which works well for narrowband systems since phase and delay can be treated interchangeably over a small bandwidth. As bandwidth increases, the frequency dependence of phase shift becomes problematic: the constant phase setting no longer corresponds to the correct time delay across the entire signal spectrum, causing beam squint and waveform distortion.

True time delay elements, by contrast, provide a fixed time delay, so the resulting phase shift increases linearly with frequency. This linear phase slope ensures that signals of all frequencies within the band experience the same effective delay through the array, aligning their phases at the combining point and maintaining beam direction. So, for wideband, high-performance arrays, especially those requiring fine resolution or long range, TTD becomes essential rather than optional.

In practice, many systems adopt hybrid architectures that combine phase shifters and TDUs. Phase shifters can handle fine steering around a nominal direction or serve narrowband modes, while TDUs provide coarse or wideband delay control to prevent squint across the full band. The design challenge is to balance cost, die area, power, and complexity against bandwidth and performance goals, choosing where in the array hierarchy (element, subarray, or tile level) TDUs should be inserted.

Integrating TDUs into AESA tile and subarray architectures

In AESAs, antenna elements are often grouped into modular tiles, each containing beamforming ICs (BFICs), RF front-ends, and other control circuitry. Within each tile, TDUs can provide precise synchronization across elements or subarrays, ensuring that signals combine coherently in the desired direction over wide bandwidths. Typical TDUs offer delay steps in the picosecond range, allowing fine-grained control of beam pointing and compensation for channel-to-channel variations.

Wide instantaneous bandwidth is particularly important for high-resolution radar, where shorter pulse widths improve range resolution but demand larger bandwidth. For example, a ULA operating at a 10 GHz center frequency with a 1.5 GHz signal bandwidth and 16 elements with half-wavelength spacing may be limited to a 60-degree scan range if phase-only steering is used and signal degradation must be held within acceptable bounds. Beyond such limits, true time delay, rather than approximate phase-based delay, is required to preserve beam integrity and resolution across the full spectrum.

Calculating TTD requirements for ULA design

In uniform linear arrays, the delay required at each element can be derived from the desired scan angle, element spacing, and operating frequency. A phase shifter with a given resolution, say a 6-bit device with a least significant bit (LSB) of 5.625 degrees, corresponds to a particular minimum time delay increment at the operating frequency; at 10 GHz, this phase step translates to approximately 1.5 picoseconds of delay. To replace such a phase shifter with a TDU, the delay unit must support at least the same or finer time resolution to maintain equivalent steering granularity.

For arrays with up to 16 elements per side and scan angles up to about 60 degrees, the total required delay at the outer elements can reach around 650 picoseconds. Designers may implement this total delay using cascaded TDUs or a combination of coarse and fine delay stages, distributing the delay across the RF chain to meet both performance and implementation constraints. This approach enables larger or more agile arrays while maintaining precise control of beam pointing over wide frequency ranges.

TDU topologies: Switched lines, ATLs, and LC networks

TDUs can be realized with several circuit topologies, each offering trade-offs in terms of noise, insertion loss, die area, and linearity. Switched delay lines use multiple physical line lengths selected by RF switches to create discrete delay values; they tend to provide low noise and low insertion loss but require more chip area, especially at longer maximum delays.

Artificial transmission lines (ATLs) use synthetic line structures to achieve compact delay implementations, trading size for higher loss and potentially increased noise. LC-based delay networks implement analog delay using lumped inductors and capacitors, offering fine control and tunability but adding design complexity and sensitivity to component tolerances.

Digital delay lines, familiar with digital signal processing, use switched digital paths to provide quantized delays, making them attractive for architectures that need both coarse and fine control and may integrate closely with digital beamformers. Each topology represents a different balance between delay precision, footprint, insertion loss, and linearity, and system-level simulations are typically required to identify the optimal choice for a given application.

Integrating TTD in RFICs: Monolithic microwave circuits for wideband phased arrays

Historically, true time delay could be implemented with coaxial cables, optical fibers, or microstrip and stripline networks, but these approaches often struggle with size, weight, and cost in large, high-frequency arrays. Monolithic microwave integrated crcuits (MMICs) now provide a more practical and scalable solution, integrating delay elements, switches, and equalization within compact RFICs.

Advances in CMOS, GaAs, and MEMS technologies have reduced the size and power consumption of TTD circuits while improving bandwidth and delay resolution.

A typical MMIC-based TDU may combine switched or artificial transmission lines with wideband distributed gain amplifiers and gain-slope equalizers to compensate for frequency-dependent loss and maintain flat group delay across the band. Integration with beamforming ICs and RF front-end modules allows designers to place TTD functionality at the element, subarray, or tile level, trading semiconductor area against array-level performance and flexibility.

Why TTD matters: Wideband array performance and future-proof AESA design

From a system perspective, true time delay provides consistent beam steering across wide frequency ranges, improving signal quality, resolution, and link margin at the band edges. By effectively eliminating beam squint across the operating bandwidth and preserving coherent combining across the array, TTD enhances both EIRP and G/T, directly impacting radar detection performance and communications reliability.

In demanding environments and applications, such as defense radar, satellite payloads, and next-generation wireless backhaul, this can be decisive in meeting performance requirements. Beyond immediate performance gains, TTD also supports future proofing. As bandwidth requirements continue to grow and spectral environments become more complex, architectures that already incorporate wideband-capable TDUs and hybrid TTD/phase-shifter beamforming are better positioned to adapt without wholesale redesign.

For engineers and decision-makers, the key takeaway is that while phase shifters remain suitable for narrowband or cost-sensitive systems, TTD is becoming a critical enabler of competitive, high-performance wideband phased arrays.

David Schnaufer is technical marketing communications manager at Qorvo, where he leverages his extensive technical and strategic experience to develop insightful, thought leadership content. Throughout his career at Qorvo, he has served several roles, including senior manager of strategic marketing and product marketing manager.

Related Content

• Beam steering: One of 5G’s components
• Phased array antennas: From military to 5G
• Beam steering: one of 5G’s many technologies
• Millimeter wave beamforming and antenna design
• Testing phased-array antennas for satellite communication

The post TTD for wideband phased array beamforming: Eliminating beam squint in AESA appeared first on EDN.

Picture a satellite holding its course high above Earth, its mission dependent on flawless orientation, or an electric vehicle with a high-voltage battery that demands exact current monitoring to safeguard performance and safety. In these moments, precision is not a luxury—it is mission-critical.

Conventional magnets and commodity sensors falter under the weight of noise, drift, and limited sensitivity. The fluxgate sensor changes that equation, harnessing magnetic saturation to deliver scientific-grade accuracy and bridging the gap between everyday detection and the uncompromising demands of advanced engineering.

Fluxgate: Saturation as the gatekeeper

At the core of a fluxgate sensor lies a high-permeability ferromagnetic material that acts as a magnetic modulator. Driven by an alternating current, the core is periodically pushed into saturation—a state where its ability to conduct magnetic flux collapses. This creates a “magnetic gate”: when unsaturated, the core concentrates the external magnetic field into the sense coil; once saturated, its permeability drops, effectively closing the gate to that field.

This controlled gating modulates the external flux, inducing a voltage in the sense coil. In a perfectly balanced, zero-field condition, the drive signal produces only odd harmonics. The presence of an external field breaks that symmetry, introducing even harmonics, most notably the second harmonic, which provides a precise, linear measure of the field’s strength. By exploiting the non-linear transition into saturation, fluxgate sensors achieve sensitivity and stability far beyond ordinary inductive detection.

Fluxgate anatomy: Core, drive, and sense

A fluxgate sensor is built around three essential elements working in concert. At its heart is the magnetic core, typically a ring or rod made from high-permeability alloys such as Permalloy or Mu-metal, where hysteresis and saturation take place. Wrapped around this core is the drive coil, the “motor” that pushes the material into saturation by applying an alternating current.

Completing the system is the sense coil, the “ear” that listens for changes in magnetic flux and captures the second harmonic signal produced when the external field interacts with the saturated core. Together, these components transform invisible magnetic influences into precise, measurable data.

Figure 1 A fluxgate sensor employs a ferromagnetic core, drives it periodically into magnetic saturation via a drive winding, and captures the modulated magnetic flux with a sense winding. Source: Author

Note at this point that while standard open-loop fluxgates typically rely solely on drive and sense windings, closed-loop configurations introduce a feedback winding to enhance precision.

Interestingly, some advanced designs consolidate these roles, utilizing a single winding for both sensing and feedback. By employing time-multiplexing—rapidly switching between sensing the field and applying a compensation current—or using frequency filtering to isolate the signals, engineers can achieve closed-loop performance without a physically distinct third coil. Even in these integrated designs, the fundamental function of feedback remains the key to the sensor’s accuracy and long-term stability.

Ring-core revolution: How Goubau redefined fluxgate

The Goubau-type fluxgate sensor, developed by Rudolf Aschenbrenner and Georg Goubau in the mid-1930s, represents a pivotal milestone in the evolution of magnetic field measurement. Moving beyond earlier parallel-rod designs, they pioneered the ring-core architecture, which utilized a closed-loop magnetic path to achieve a remarkable resolution of 0.3 nT, a precision that was revolutionary for its time.

By driving the core into periodic saturation via an excitation current, the sensor “gates” external magnetic flux to induce a voltage proportional to the ambient field, specifically isolating the second harmonic frequency. This robust, self-shielding design effectively minimized magnetic noise and established the fundamental blueprint for modern high-precision magnetometry, eventually enabling the transition from land-based geophysical observatories to the sophisticated, solid-state sensors deployed in contemporary space exploration missions.

Why use fluxgate sensors

Fluxgate sensors distinguish themselves through a blend of sensitivity, stability, and versatility that makes them indispensable in demanding applications. Their high sensitivity allows them to detect magnetic fields thousands of times weaker than Earth’s, opening the door to ultra-fine measurements in geophysics and aerospace. They exhibit exceptionally low drift, delivering long-term stability that outperforms Hall-effect sensors and ensures accuracy over extended periods.

Equally important, they operate effectively with both DC and low-frequency AC fields, giving engineers a versatile tool that adapts to a wide range of measurement scenarios. Yet these high-performance capabilities come with trade-offs: fluxgate sensors are generally larger, more complex, and consume more power than compact, chip-based alternatives such as Hall-effect or magnetoresistive sensors. As a result, they are best suited for precision-critical environments where data integrity outweighs the need for extreme miniaturization.

Getting to modern integration, digital fluxgate sensors address the traditional limitations of size and complexity by combining the sensing core with on-board electronics for signal processing, compensation, and calibration. By digitizing the harmonic output directly at the sensor, they reduce noise, simplify interfacing, and improve long-run stability.

These integrated designs make fluxgates more practical for embedded systems and field instruments, ensuring the technology remains relevant even as compact alternatives such as Hall-effect and magnetoresistive sensors dominate consumer applications.

Figure 2 This 1-axis fluxgate magnetometer delivers linearized, temperature-compensated magnetic field data directly in nanotesla (nT) for precise and stable measurements. Source: FG Sensors

From principles to applications

Building on these principles and modern integrations, fluxgate technology finds compelling expression in real-world applications. Whether guiding a compass to resolve Earth’s faint magnetic field, stabilizing aircraft heading systems, or measuring current with precision in power electronics, the same saturation-based gating mechanism underpins each use case. By translating subtle magnetic influences into stable, linear signals, fluxgates bridge the gap between theory and practice, proving their worth wherever accuracy and reliability are paramount.

Fluxgate compass

Among the earliest and most enduring applications of fluxgate technology is the fluxgate compass. Unlike mechanical compasses that rely on a freely moving needle, fluxgate compasses electronically resolve Earth’s magnetic field by measuring its vector components. The sensor’s saturation-based gating mechanism allows it to detect the field with remarkable precision, even when the signal is thousands of times weaker than ambient noise sources.

This electronic approach offers several advantages. Fluxgate compasses provide continuous digital output, making them easy to integrate with navigation systems in ships, aircraft, and spacecraft. They remain stable in dynamic environments where mechanical compasses falter—such as near ferrous structures, in turbulent motion, or under vibration. Their low drift ensures relatively long-time accuracy, which is critical for heading reference systems and autopilot integration.

However, these benefits come with trade-offs. Fluxgate compasses are more complex and consume more power than simple magnetometers, and their size can be a limiting factor in portable consumer devices. As a result, they are best suited for mission-critical navigation where reliability and precision outweigh the need for extreme miniaturization.

Figure 3. An electromagnetic fluxgate compass measures the Earth’s magnetic field directly to provide heading data, serving as a reliable alternative or backup to the primary gyro system. Source: Marine Data Systems

Current sensing

Fluxgate sensors also play a critical role in precision current measurement. When a conductor carries current, it generates a magnetic field proportional to the flow. By placing a fluxgate sensor around or near the conductor, this field can be resolved with exceptional accuracy, enabling non-intrusive current sensing.

The saturation-based gating principle ensures linearity across a wide dynamic range, making fluxgates particularly valuable in high-power systems where both small leakage currents and large load currents must be monitored reliably.

The advantages are clear: fluxgate current sensors offer DC capability, unlike many transformer-based solutions that only respond to AC. They also deliver low drift and high stability over extended periods, which is essential for monitoring in power electronics, grid systems, and aerospace applications. Their ability to detect minute variations makes them suitable for fault detection, efficiency optimization, and protective relaying.

As with other fluxgate applications, trade-offs exist. These sensors are larger and more complex than compact Hall-effect devices, and their higher power consumption can be a limiting factor in portable or consumer contexts. Yet in mission-critical environments—such as aircraft power distribution, renewable energy systems, or precision laboratory instrumentation—their accuracy and reliability outweigh these constraints, making fluxgate current sensing a trusted solution.

Figure 4 This fluxgate closed-loop current sensor measures DC, AC, pulse, and irregular waveform currents while providing galvanic isolation. Source: Chen Yang Technologies

As a quick aside, you think of DRV421 from TI. It’s a great pick for magnetic closed-loop current sensing because it handles both AC and DC with robust isolation. What makes it stand out is that it packs a proprietary fluxgate sensor and signal conditioning into one chip, keeping your part count low. Because the fluxgate has such low offset drift, the overall measurement precision is hard to beat.

Heading and attitude reference systems

Fluxgate sensors also underpin heading and attitude reference systems, where precise orientation data is vital for navigation and control. By resolving the vector components of Earth’s magnetic field, fluxgates provide a stable magnetic heading that can be fused with gyroscopes and accelerometers to deliver complete attitude information. This integration is especially important in aircraft and spacecraft, where reliable orientation must be maintained despite vibration, acceleration, and environmental disturbances.

The strength of fluxgates in this role lies in their ability to deliver accurate, drift-resistant magnetic references. Unlike mechanical compasses, they remain unaffected by motion dynamics, and unlike gyroscopes, they do not accumulate error over time. When combined in modern inertial navigation systems, fluxgates serve as the magnetic anchor that ensures long-term stability and confidence in heading data.

As with other applications, trade-offs exist. Fluxgate-based reference systems are more complex and power-hungry than compact magnetometers, and they require careful calibration to mitigate local magnetic interference.

Yet in mission-critical aviation, marine, and space contexts, their precision and reliability make them indispensable, ensuring that orientation data remains trustworthy under demanding conditions. As an aside, you may look at the systems called HARS or AHRS; regardless of the acronym, the fluxgate remains the indispensable ‘magnetic North’ for the entire sensor suite.

Future directions

While fluxgate sensors have long been valued for their precision and stability, ongoing research continues to push the technology forward, and this is where enthusiasts, makers, hobbyists, and engineers can play a role. Here, miniaturization efforts aim to reduce size and power consumption, making fluxgates more competitive with compact magnetoresistive and Hall-effect devices.

Hybrid designs that combine fluxgate cores with MEMS or digital compensation circuits promise improved performance in embedded systems. At the same time, advances in materials and signal processing are extending sensitivity into new ranges, opening opportunities in geophysics, defense, and renewable energy monitoring.

For those eager to experiment, prototyping with modules, integrating fluxgates into navigation projects, or blending them with modern microcontrollers offers a chance to push boundaries and contribute to the next wave of innovation.

As sensor ecosystems evolve, fluxgates are likely to remain the choice for applications where accuracy, drift resistance, and DC capability are non-negotiable. Their integration into modern electronics ensures that, even as alternatives dominate consumer markets, fluxgates continue to serve as the trusted backbone of high-reliability instrumentation.

Fluxgates remind us that precision isn’t just measured; it’s built, tested, and carried forward by those who dare to innovate.

T. K. Hareendran is a self-taught electronics enthusiast with a strong passion for innovative circuit design and hands-on technology. He develops both experimental and practical electronic projects, documenting and sharing his work to support fellow tinkerers and learners. Beyond the workbench, he dedicates time to technical writing and hardware evaluations to contribute meaningfully to the maker community.

Related Content

• Tiny magnetometer ups sensitivity
• Magnetic Sensors for Motion Control
• Magnetometers: Sensing the invisible fields
• Transducer Options for Safe, Precise Current Sensing

The post Fluxgate basics: How magnetic saturation changes everything appeared first on EDN.

As the automotive industry continues to shift toward software-defined vehicles (SDVs), autonomous driving, and connected vehicles, it raises challenges around performance, reliability, and security. Component makers have a big role to play by delivering next-generation designs that support the transition to these new automotive architectures.

The July/August issue takes a look at advances happening at the component level that are enabling next-generation automotive technologies. These range from zonal microcontrollers (MCUs) and gallium nitride (GaN) and silicon carbide (SiC) power devices to connectors and LEDs/LED drivers. We also look at safety and security challenges in SDVs.

As vehicle electrical/electronic architectures evolve and the automotive industry transitions to SDVs, it raises new technical challenges for automakers. In particular, the move from domain-based to zonal architectures that group vehicle functions presents challenges, as each zone controller needs to handle a wide range of tasks. This means the ECUs in a zonal design require compute capabilities that can handle both time-sensitive and compute-intensive workloads concurrently.

“In a zonal architecture, each zone of a vehicle, such as front, rear, or cabin, has a high-performance controller managing local devices and communicating with other controllers over high-speed networks,” said Paul S. Lee, senior director, automotive microcontrollers, zonal segment leader, at NXP Semiconductors.

Although this approach is faster to update, easier to scale, less complex, and even cheaper, it also presents new technical challenges for automakers, Lee said. He discusses key challenges in the move to SDVs and how zonal MCUs are building the foundation for the next generation of SDVs.

Another big challenge in SDVs is the cybersecurity threat. Rambus is calling for a collaborative effort among engineers, security teams, and end users to create a secure SDV ecosystem.

“SDVs continuously evolve through over-the-air updates, unlocking new features, optimizing performance, and enhancing safety over time,” said Paul Karazuba, VP of product marketing for silicon IP at Rambus. “While this shift continues to enable greater connectivity, automation, and personalization, it also expands the cybersecurity threat landscape,” and as “SDVs integrate with cloud systems, mobile apps, and AI-driven features, they become more vulnerable to cyberattacks.”

Karazuba discusses this expanding cybersecurity threat landscape and how to ensure security frameworks that enable SDV features while protecting user safety and data privacy. “Security must be integrated from the ground up, beginning at the chip and silicon IP level to prevent hardware-based exploits.”

(Source: Adobe Stock)

Advances in autonomous vehicles (AVs) and advanced driver-assistance systems are also driving the need for improvements, particularly in radar, LiDAR, and cameras for safer systems. Innovations in these technologies, powered by sensor fusion, are enabling vehicles to understand their environments in real time.

Contributing writer Stefano Lovati explores how perception and sensor fusion are driving evolution and innovations in the three main categories of automotive sensors: radar, LiDAR, and cameras. Lovati said that while every sensor type has its own limitations, sensor fusion “bridges this gap by intelligently combining data from sensors using advanced algorithms.”

Bitsensing tells us that 4D imaging radar is critical to AV commercialization and safe autonomous driving. The latest radar systems work at ranges of more than 200 meters, have low power consumption, and can easily be integrated into vehicle systems, with manufacturers already building systems designed specifically for the commercial AV market, said Jae-Eun Lee, CEO of bitsensing Inc.

However, Lee explained that many 4D radars are developed for ADAS rather than being built for full driverless functionality.

4D radar is important for the rapid commercialization of AV technology because it enables the rapid classification of different kinds of road users, but “to really drive the commercial AV market forward, it’s also vital that sensors are purposely designed for full autonomy, rather than being repurposed from devices for the consumer market,” he said.

Also reshaping automotive electronics are GaN and SiC power devices. These devices are being increasingly adopted into vehicles thanks to their faster switching and higher efficiency.

Lovati reports that GaN and SiC are no longer considered exotic semiconductors, and the automotive industry is leveraging their capabilities to switch faster, tolerate higher blocking voltages and temperatures, and dissipate less energy than conventional silicon.

He examines the current state and next steps for both SiC and GaN technologies across key automotive areas, including traction inverters, on-board chargers, DC/DC converters, and auxiliary power systems.

Don’t miss the connector and cable product roundup, looking at the latest rugged and flexible interconnects for high-reliability applications, including automotive, industrial, and military/aerospace. These connectors deliver miniaturization, reliable performance, and easier integration.

We also look at some of the latest innovations in automotive LEDs and LED drivers. Many of the latest LED developments focus on delivering smaller form factors for space-constrained and sleeker designs, improved thermal performance, and flexible color control. LED driver manufacturers also deliver simpler designs for easier integration and space savings, as well as advancements in areas such as packaging and heat dissipation.

The post Next-gen components power safer, smarter vehicles appeared first on EDN.

The premise that a supposed-clone rechargeable battery is more economical than its “branded” counterpart is all well and good…unless you’re unable to actually recharge it.

As my accretion of previously-owned photography equipment continues unabated, so too grows the pile of batteries for powering them. Many of the cells are camera manufacturer-branded, but in a few situations, what’s arrived post-purchase are third-party “clones”, with the quotes referencing the hit-or-miss reality in achieving the suppliers’ desired exact-duplicate aspirations.

Recently added to my gear inventory, for example, is an OM-1 (the newer digital version, not its same-named film-based classic precursor) from Olympus (now OM System).

It showed with a third-party BLX-1 battery (7.2 V, 2280 mAh) inside it. Olympus’ BCX-1 charger unsurprisingly had no issue with the official BLX-1 cell.

Unfortunately, however, it balked at accepting the third-party mimicker.

Typically, this outcome results from a failed upfront interrogation of the battery by the charger (or camera, for that matter), done over an identification, status, or functionally equivalent bus. While cloning a simple manufacturer-and-device ID code combination stored in nonvolatile memory is rather straightforward, impersonating more complex hardware such as the entire embedded battery management system (BMS) is a more challenging endeavor.

I also wasn’t up for the common “solution” to this situation—the third-party battery supplier encouraging the user to buy its own charger—even if it were feasible. Since this battery is supplier-unbranded, I wouldn’t know where to even start looking for a copacetic charger companion. So, it went under the internal-analysis knife for my and readers’ shared educational benefit.

Electrical contact-function guesstimates

Here are some overview shots of the third-party BLX-1, as usual accompanied by a 0.75′′ (19.1 mm) diameter U.S. penny for size comparison purposes. Top:

Bottom:

Note the four sequential contacts marked “+”, “T”, “I” and “-“.

Published specifications for batteries like the one I’m looking at today are hard-to-impossible to come by, given that the camera manufacturer understandably doesn’t want to encourage cloning for economics (“branded” batteries are more expensive, therefore highly profitable to the supplier) and broader camera and brand damage-avoidance reasons. That said, the functions of “+” and “-“ are, unsurprisingly, related to the voltage and current involved in the fundamental cell-charging and -discharging functions, the latter for camera-powering purposes.

“T” typically references “temperature”, with the contact connected to an integrated negative temperature coefficient (NTC) thermistor or other sensor to monitor the internal cell(s) and alert the charger to potential overheat conditions. And “I”, perhaps short for “information” or “identification”, references the earlier-noted interrogation initially done by both charger and camera after battery insertion and power-on, and ongoing from that point on, presumably implemented by a bidirectional single-data-pin serial communications protocol of some sort.

Onward, with the comparatively bland other end, followed by the left and right sides.

Actualizing unexciting-dissection aspirations

Now to get inside. You’ve likely already noticed the tempting seam running along the entire circumference, dividing the battery roughly into two halves. Its ultrasonic welded foundation meant that simple heat application wouldn’t suffice to get them apart…not that I’d want to do that anyway, given the just-alluded-to battery chemistry overheating side effects.

I also didn’t know how (if at all, vs. elementary “pouch” structures) the cell(s) inside were encased, giving me pause when it came to contemplating alternatively cutting into the seam. And construction aside, I also didn’t want to inadvertently short out a cell via a misplaced blade. Yikes!

I eventually settled on a methodology involving my hobbyist vise and the meticulous back-and-forth use of my hacksaw blade (versus my also-considered Dremel tool’s cutting wheel…heat concerns again, though…), which thankfully worked like a charm with no “exciting” side effects.

The two serial-connected 3.7V Li-ion cells were cylindrical in form factor and unmemorable.

Note that I straightaway severed the metal straps connecting them both to the PCB and to each other, in a nod to my earlier mentioned short-circuit outcome concerns.

I’d wager, however, that the mini-PCB, with contacts on one side and componentry on the other, was always of greater interest to all of you (as it certainly was to me).

Mystery ICs

Flip it over, remove the obscuring rubberized strips that normally provide the mini-PCB with both shock-absorptive and electrically insulative isolation from the cells’ terminals.

And the electronics “guts” come into full view.

The eight-lead IC U1 at far left is labeled:

8205A
Q121M1

It appears to be a dual N-channel MOSFET, a common element of elementary lithium battery protection circuits. The six-lead IC U2, seen directly to its right, is labeled:

20DBUE

Reader insights are welcomed on this one; Google was of no help! Although I can’t help but wonder, revisiting the earlier-referenced schematic, if it’s a rudimentary battery-protection IC?

Skipping past a mess of passives, the next notable chip is a 20-lead IC whose topside markings were unfortunately buffed out…that is, if they ever existed in the first place! I presume it’s the battery charge controller; make and model unknown, alas. That said, as a conceptual example, I’ll point you toward Texas Instruments’ bq2400x series, multiple of which support dual-cell assemblies (for which balancing will be necessary) and come in various 20-contact packages.

At far right is another enigma, this one six-lead and PCB-notated as U4 (or at least I think that’s what it says; the inconveniently located through-hole vias at the top don’t help). Character(s) at far left on the topside stamp represent(s), I’m guessing, an unfamiliar-to-me company logo that my limited available keyboard options won’t allow me to represent. The last four, ironically, are:

U4UH

I presume the commonality of the first two with the PCB mark is nothing more than a mere coincidence. IC identity suggestions, readers?

And with memories of recent-past short-circuited, overheating batteries still fresh in my mind.

And knowing that the battery’s guts would be sitting in my office for several more weeks prior to publication of my teardown writeup, I concluded this portion of the project by amply wrapping both cells in insulating masking tape prior to moving on.

More to come

I’ve got two more batteries still sitting in the teardown queue, but as this initial segment went longer than initially anticipated (then again, what else is new, right?) I’ve decided to save them for part 2 in this now-series, scheduled for publication next week. Until them, I welcome your feedback in the comments on what I’ve covered so far!

—Brian Dipert is the associate editor, as well as a contributing editor, at EDN.

Related Content

• Engineering tradeoffs: a camera case study
• NOCO’s Genius 1: A trickle charger that tries harder
• Single-battery failures in multi-battery arrangements: diagnosing selective cell derangements
• Not smart, but solar: Analyzing another thermo-plus-hygrometer

The post Dissecting third-party camera batteries, part 1: Functional misbehavior appeared first on EDN.

Advances in autonomous driving and advanced driver-assistance systems (ADAS) now enable vehicles to understand their surroundings in real time, a complex process based on the concepts of perception and sensor fusion.

Perception refers to the ability to detect and classify objects, recognize traffic signs, track pedestrians, and map the road. However, every type of sensor has its own physical limitations. Sensor fusion is the technology that bridges this gap by intelligently combining data from sensors using advanced algorithms.

In this article, we will explore how perception and sensor fusion are driving evolution and innovations in the three main categories of automotive sensors: radar, LiDAR, and cameras. We also highlight several radar, LiDAR, and camera products with advanced features to improve ADAS imaging and perception.

Radar performs in harsh environments

Automotive radar offers excellent performance in tough conditions, such as fog, rain, and darkness, where cameras and LiDAR are less effective. The introduction of 4D imaging radar has added elevation (height) to the standard range, velocity, and azimuth outputs. 4D radar can thus generate dense point clouds that were once available only with LiDAR. According to MarketsandMarkets, the 4D imaging radar market was valued at $390 million in 2025 and is expected to grow to $1.2 billion by 2030, at a compound annual growth rate of 25.2%.

Hirain Technologies has developed the LRR615, a long-range imaging radar built around Arbe Robotics Ltd.’s 4D imaging radar chipset solution. The radar system is the first to be equipped with a high-density waveguide antenna. This feature provides improved image clarity, detection sensitivity, and signal integrity.

Designed to be cost-effective and manufacturable on a large scale, the LRR615 can be paired with cameras in autonomous-driving systems, providing an alternative to LiDAR. After integrating, calibrating, and validating the device, Hirain is setting up the manufacturing process to achieve an annual production of 10,000 units.

Arbe’s chipset (Figure 1) is a multichip architecture that integrates three proprietary, automotive-grade integrated circuits that process ultra-high-resolution data. The chipset can process real-time data from 2,304 virtual channels, achieve 3-Tbits/s equivalent processing throughput, and provide over 10,000 detections at 20 fps.

Arbe’s chipset is based on GlobalFoundries’ (GF’s) proprietary 22FDX process technology. This platform, specifically addressing automotive radar, integrates RF, analog, and digital processing blocks on the same die. This reduces system costs and accelerates time to market. According to GF, using its technology, Arbe is the first in the industry to create a real-time, 4D image of the surrounding environment, achieving a 1° resolution.

Figure 1: Arbe’s automotive-grade chipset integrates a safety processor, security, dual-core DSP, and application processor. (Source: Arbe Robotics Ltd.)

Another relevant application of automotive radar is in-cabin monitoring. An example is Texas Instruments Inc.’s AWRL6844, a 57- to 64-GHz mmWave radar sensor designed for occupancy monitoring, including seat-belt reminder systems, child-presence detection, and intrusion detection (Figure 2).

The AWRL6844 is a low-power device integrating four transmitters and four receivers. This high-resolution sensing data is processed by specific AI algorithms running on a customizable, on-chip hardware accelerator and DSP. This single-chip solution improves detection accuracy, reduces processing time, and enables a safer driving environment.

Figure 2: The TI AWRL684x mmWave sensor device employs FMCW radar technology to support multiple in-cabin applications. (Source: Texas Instruments Inc.)

Infineon Technologies AG offers a similar product, the XENSIV BGT60ATR24AIP 57.7- to 62.4-GHz radar sensor based on FMCW technology. Available in a compact, 8 × 8-mm2 package with antenna-in-package technology, the device features ultra‑low power consumption, high precision, and advanced sensing, making it suitable for contactless, high-accuracy in‑cabin monitoring.

LiDAR advances with better perception and identification

MicroVision Inc., a company specializing in advanced perception solutions that recently acquired the assets from Luminar Technologies, introduced its Tri-LiDAR architecture. This solution integrates two MOVIA S short-range sensors (placed on the front corners) with one forward-facing HALO long-range LiDAR, delivering continuous, 360° environmental coverage (Figure 3).

The company’s software platform performs the real-time fusion of the data coming from all the sensors and generates a single, high-fidelity point cloud. This enables accurate object detection, classification, and tracking, delivering a real-time perception system.

According to the company, Tri-LiDAR provides three main benefits: a reduction in the power consumption of each sensor, a reduction in the packaging of each sensor, and a cost reduction of the system.

Figure 3: Top view of the MicroVision Tri-LiDAR system (Source: MicroVision Inc.)

Aeva Inc., a company specializing in sensing and perception systems, has licensed Cadence Tensilica Vision DSP IP to support the signal-processing tasks of its 4D LiDAR systems.

Tensilica Vision DSPs’ low-power architecture and Tensilica Instruction Extension language make Tensilica DSPs suited for applications in which real-time signal processing, low latency, and high efficiency are mandatory. According to Aeva, the flexibility and performance of Cadence’s Vision DSP technology will improve the perception and scalability of its solutions, addressing automotive and industrial applications.

Hesai Technology, a company specializing in 3D perception, announced the Picasso 6D Full-Color LiDAR SPAD-SoC, a solution that natively captures 3D spatial geometry (X, Y, Z) and 3D color data (R, G, B) on a single chip, eliminating the need for fusion of separate camera and LiDAR data.

By performing the sensor data fusion directly at the silicon level (the single-photon avalanche-diode SoC), the Picasso chip produces high-resolution, colorized point clouds simultaneously, allowing for better identification of objects such as traffic lights, lane markings, and construction zones. Hesai’s ETX LiDAR, upgraded to support up to 4,320 channels, will integrate this technology and will be available in the second half of 2026.

Lumotive, a company specializing in programmable optical semiconductors, has introduced a solid-state LiDAR platform that combines its commercially available LM10 Light Control Metasurface (LCM) with the ADS6311 Hawk sensor from Adaps Photonics.

The solution (Figure 4) delivers a 180° horizontal field of view and operates at 30 fps, eliminating blind spots, improving the tracking of fast-moving objects, and reducing the number of sensors required. Lumotive’s LCM technology electronically steers light at semiconductor speed, without encountering the limitations associated with mechanical scanners and fixed-channel VCSEL arrays. In addition to 180° horizontal coverage, the sensor offers up to 140° vertical coverage, configurable through software to optimize range, resolution, and frame rate.

Figure 4: The architecture of Lumotive’s solid-state LiDAR system doubles the frame rate typically achieved by many direct ToF LiDAR systems while extending sensing distances to as much as 50 meters. (Source: Lumotive)

Cameras shift to 8-MP sensors

Cameras are rapidly migrating to 8-MP sensors, representing the new baseline for ADAS front and side cameras. The higher resolution directly increases the detection range at highway speeds, enabling confident object classification at distances that 2-MP and 5-MP sensors cannot reliably achieve.

Omnivision introduced the OX08D20 8‑MP CMOS automotive image sensor based on its proprietary TheiaCel technology. The device is an improved version of the OX08D10 sensor for exterior cameras widely used in ADAS and autonomous-driving systems.

The OX08D20 image sensor features a 60-fps frame rate, 2× higher than its predecessor, OX08D10, enabling dual-use cameras. With 60 fps, the video flows more smoothly. This allows car manufacturers to save money, space, and wiring by using one camera to handle both background autonomous-driving tasks and real-time visual displays for the driver. The sensor also supports the latest cybersecurity standard MIPI CSE 2.0 (Camera Service Extensions v2.0) developed by the MIPI Alliance.

Omnivision’s TheiaCel technology has been designed to capture high-quality images even in extreme lighting conditions. It achieves high dynamic range (HDR) using a single exposure. In this way, the LED flicker experienced in traditional HDR sensors is eliminated.

Sony Semiconductor Solutions introduced the IMX828, the industry’s first 8-MP CMOS image sensor for automotive cameras featuring a built-in MIPI A-PHY transmission interface. Traditional automotive camera systems require externally mounted serializer chips to transfer data safely to the vehicle’s electronic control unit. By embedding the MIPI A-PHY interface directly into the sensor, Sony eliminates the need for this additional hardware.

This feature enables a reduction in board size and module power consumption and limits heat generation. The chip also integrates a proprietary error-handling circuit that resists external noise disruptions.

NXP Semiconductors’ 4K MIPI CMOS camera module (IMX-OS08A20) is a high-performance development tool for consumer, industrial, and automotive vision systems. It is built on OmniVision’s 8-MP OS08A20 sensor and adopts PureCel and Nyxel technologies to capture 4K Ultra-HD video at 60 fps.

The development kit includes the 8-MP sensor module, a MINI-SAS interface cable, and an adapter board. It is designed to plug directly into the NXP i.MX 8M Plus Evaluation Kit. The module’s high-resolution performance makes it well-suited for automotive in-cabin applications, such as driver-monitoring systems and occupant-monitoring systems.

The post Designer’s guide: Radar, LiDAR, and cameras advance ADAS appeared first on EDN.

LED manufacturers continue to enhance their LED designs for automotive lighting, enabling greater differentiation in the car’s exterior and interior illumination as well as improving safety features. Many of the latest developments focus on several key areas: smaller form factors for space-constrained and sleeker designs, improved thermal performance, and flexible color control.

LED driver developments go hand in hand with these advances to support these next-generation LEDs, focusing on advancements in packaging, heat dissipation, and simpler designs for easier integration and space savings.

Here is a selection of LED and LED drivers introduced over the past year, targeting automotive exterior and interior lighting applications. They focus on a range of improvements that deliver smaller form factors, greater heat dissipation, higher system efficiency, enhanced light output, and precise color control.

Automotive LED innovations such as compact, high-luminance designs enable sleeker lighting systems while maintaining uniform, energy-efficient light output. (Source: Adobe Stock)

A new generation of LEDs

Some of the latest automotive LED designs address the demand for sleek front lighting. One example is ams Osram’s OSLON Compact RM for next-generation slim headlamp systems. It addresses design aesthetics in automotive lighting with its high luminance, compact form factor, homogeneous light, and color appearance, allowing for the creation of signature lighting elements for brand identity, the company said.

The Compact LED is a 0.5-mm2 rectangular high-current chip, housed in a compact ceramic package. The small size enables optical systems with heights as low as 10 mm, enabling ultra-slim headlamp designs that were previously difficult to achieve, according to ams Osram. The two-pad package design supports solder stability on aluminum boards, suiting it for a variety of automotive lighting applications.

The LED delivers improved optical efficacy through its adapted light-emitting area (LEA) of 0.6 × 0.9 mm with an aspect ratio of 1:1.5. It features high luminance and uniform light output, free from dark zones, while maintaining high energy efficiency, a key factor for EVs.

The OSLON Compact RM for advanced front-lighting applications targets three light functions: low beam, static high beam, and adaptive driving beam (ADB) LED matrix systems. Thanks to its rectangular LEA, vertically oriented within the package, the OSLON Compact RM enables precise pixel-to-pixel alignment and provides a greater vertical light spread in ADB systems. At a driving current of 1 A, it claims an impressive luminance of 209 Mnits, which ensures maximum optical performance even with small lens components, according to the company.

Ams Osram’s OSLON Compact RM (Source: ams Osram)

Ams Osram also enhanced its offerings for automotive interior applications with the launch of its OSIRE E3030 RGB LED with significantly enhanced light output. Aimed at next-generation ambient lighting solutions, the RGB LED pairs a high light output in the 0.5-W range with precisely controllable color variety, meeting both function and aesthetic requirements.

Depending on the selected color location, the OSIRE E3030 delivers typical luminous emissions for red and blue, ranging from 22.4 to 40 lumens or from 7.1 to 14 lumens at a binning current of 200 mA, and from 28 to 50 lumens for green at a binning current of 150 mA. It offers a wide range of available wavelengths for an expanded color gamut and individually addressable color channels for greater flexibility in terms of color selection and color mixing.

The OSIRE E3030 measures 3 × 3 × 0.6 mm, suiting it for applications with space constraints. In addition, the delta arrangement of the LED chips ensures exceptional color-over-angle performance, according to the company.

The OSIRE E3030 is also resistant to vibration and temperature fluctuations, meeting automotive standards. It is AEC-Q102-qualified.

Ams Osram’s OSIRE E3030 RGB LED (Source: ams Osram)

Also claiming ultra-small footprints and profiles, Lumileds has introduced two LED series—the LUXEON Versat 2016 and the LUXEON Altilon SMD-A—targeting a variety of automotive lighting applications.

The LUXEON Versat 2016 automotive LED is an AEC-Q-qualified LED portfolio with a broad color and performance range, measuring 2.0 × 1.6 mm with a z-height of only 0.52 mm. The LED not only offers standard direct and phosphor-converted colors but also LED-emission spectral tuning to match transmission characteristics of foils as used in car-body and grille illumination for superior color control, Lumileds said.

Targeting animated, personalized car-body lighting, the LUXEON Versat 2016 delivers features such as singular optical elements, backlit optical surfaces, and 3D illuminated structures for car illumination beyond traditional signaling into styling and communication lighting, the company said. The automotive LED can also be used in daytime running lights (DRLs), turn, stop, tail, and side-marker applications.

Lumileds also introduced the LUXEON Altilon SMD-A LED, claimed as the thinnest single-chip addressable LED, targeting high-performance automotive forward lighting. It has a z-height of only 433 µm, which allows for optical structures to be designed with greater accuracy and efficacy. This means the optics can be designed closer to the LED, which improves optical efficiency.

The advanced package is said to increase luminance, thermal capabilities, and robustness for demanding front fog, low/high beam, and ADB.

In addition, the small edges of the LUXEON Altilon SMD-A improve contrast, measuring 1:247, and produce a sharp, natural cutoff. Lumileds said reducing the gap between LEAs to 70 µm and achieving the optimal die-to-phosphor size increases luminance for further cost-performance improvements. The series is available in four configurations: 1×2, 1×3, 1×4, and 1×5.

Lumileds’ Altilon SMD-A LEDs (Source: Lumileds Holding B.V.)

For aftermarket automotive lighting applications, Cree LED, a Penguin Solutions brand, introduced the XLamp XE-B LEDs in an ultra-compact package for directional lighting applications. This latest XLamp Element LED extends the family into a smaller form factor, measuring 0.9 × 1.4 mm, while delivering high intensity in optical systems, whether used individually or in arrays, according to the company.

Claiming new levels of performance from an extremely small light source, the automotive LED delivers up to 60% higher intensity than existing LEDs with a larger, 1 × 1-mm light-emitting surface. While it is optimized for directional lighting applications that benefit from multi-color LED designs and suited for indoor directional lighting, architectural lighting, and entertainment lighting, it also targets aftermarket automotive lighting, in which compact size, high intensity, and precise color control are all key requirements.

The XE-B LED series is built on Cree’s advanced Element platform, enabling the smallest possible distance between the LED chip and the package edge, which allows tighter spacing, improved optical control, and seamless integration with secondary optics. It also features a large, electrically isolated thermal pad that supports advanced printed-circuit-board (PCB) designs, delivering a direct thermal path to the heat sink for excellent heat dissipation and long operating lifetimes, even at maximum current, the company said.

The XE-B LEDs enable precise and consistent color mixing with a consistent 1-A maximum current across all colors and a uniform package design. It offers 17 colors plus a full range of white options.

Cree LED’s XLamp XE-B LEDs (Source: Cree LED)

LED drivers optimize automotive lighting

Targeting improved safety, aesthetics, and personalization, Diodes Inc. offers the automotive-compliant AL5958Q matrix LED driver with a 48-channel constant-current source, capable of up to 32 scans. Suited for automotive dynamic lighting, the device targets narrow-pixel mini- and micro-LED displays, which require multiple RGB LEDs to produce animated, dynamic lighting with data and information. Applications include central information displays, cluster displays, head-up displays, grill and emblem lights, body LED panels, interior lights, and rear lights.

The AL5958Q features built-in intelligent matrix display command functions that reduce the processing overhead on the local microcontroller (MCU). Key functions include automatic black-frame insertion to mitigate blurs caused by scanning switches, reduction of last-scan- and next-scan-line ghost images to eliminate ghosting from parasitic capacitors, and suppression of short-LED caterpillars.

Other features include open-LED fail lines and staggered current output delay to minimize inrush current, as well as grayscale enhancement (also known as low-brightness uniformity compensation), a grayscale clock watchdog timer, and sleep mode for power savings.

Differentiated features include the integrated 16 N-MOSFETs, allowing support of both static and dynamic systems, and multiplex-pulse-density modulation technology that enhances the refresh rate of dynamic scanning systems without increasing the frequency of the grayscale clock. This mitigates electromagnetic interference (EMI) due to high clock frequencies, Diodes said.

The AL5958Q also features high, 16-bit resolution dimming, coupled with its RGB support, for highly precise brightness control and color mixing. The current output for each color group can be configured either through three external current-sensing resistors or by programming three 6-bit global current control registers.

The device also offers advanced diagnostic features and protection mechanisms for monitoring capabilities. These include error flag registers applied to LED open/short to read out each channel using open/short detection, undervoltage lockout (UVLO) protection, and a watchdog timer.

The AL5958Q is supplied in a wettable W-QFN9090-76/SWP (Type A1) package and operates in a –40°C to 125°C ambient temperature range. Multiple AL5958Q devices can be daisy-chained without limitation. Diodes also offers a standard compliance version, the AL5958, for industrial and commercial applications.

Diodes Inc.’s AL5958Q matrix LED driver (Source: Diodes Inc.)

Lumissil Microsystems recently introduced the IS32FL3776 matrix LED driver for software-defined exterior lighting module applications. Enabling a combination of expressive and thermally efficient exterior lighting, these systems use matrix LED patterns to communicate vehicle intent, safety status, and driver-assistance cues, as well as brand identity.

The IS32FL3776, housed in a QFN-60 package, supports compact, individually addressable LED designs used in RGB mini-LED displays, full-width front-light strips, grille lamps, automated-driving-system marker lamps, and other vehicle lighting functions.

The IS32FL3776 integrates 36 constant-current sink channels and six scanning supply-switch controls to support a 36 × 6 matrix of up to 216 individually addressable LEDs. The dense matrix architecture targets large, intelligent signal display (ISD) lighting surfaces with fewer external components.

For high-quality animations, the IS32FL3776 features high-resolution, high-frequency, dithered pulse-width-modulation (PWM) control for fine brightness adjustment and a reduction in visible flicker and camera banding. Other features that help maintain uniform, artifact-free illumination across dense LED arrays include integrated current adjustment, matrix de-ghosting, low-headroom operation, and synchronized scanning.

This LED driver offers high-speed SPI and LumiBus UART interfaces that allow multiple driver ICs or distributed lamp PCBs to operate in synchronization for large-area displays and coordinated lighting animations.

The IS32FL3776 packs features for improved system efficiency and thermal performance. DCFB adaptive control is used to optimize the LED supply rail while maintaining only the headroom needed for proper current regulation, and an internal ADC and FBO feedback pin works with an external DC/DC converter to reduce driver power dissipation in large or high-brightness matrix displays.

It also supports external PMOS operation for additional thermal optimization, which moves high-side switching dissipation outside the IC package into external FETs and PCB copper, Lumissil said.

Other features include spread-spectrum PWM clocking, phase-delay control, and staged switching to help reduce supply ripple, EMI emissions, and audible-noise risk in high-brightness or high-duty-cycle ISD lighting applications; and diagnostic, protection, and communication-integrity features including LED open/short detection, ADC-based monitoring, overcurrent protection, UVLO protection, thermal shutdown, and CRC error detection.

Lumissil Microsystems’ IS32FL3776 matrix LED driver (Source: Lumissil Microsystems)

Lumissil addresses 48-V automotive systems with the introduction of the IS32LT3962 dual-channel LED controller. By using the IS32LT3962, as automotive lighting shifts from 12-V to 48-V systems, lighting designers can achieve improved power efficiency, reduced thermal stress, and lower wiring harness cost and weight, according to the company.

The IS32LT3962 drives two independent high-voltage LED strings for automotive applications such as high-/low-beam headlights, DRLs, and turn signals and enables lamp driver modules to support two functions (e.g., high beam and low beam) with a single IC to reduce space. The dual-output channel enables independent channel brightness control, with combined analog and internal/external PWM dimming for more compact lighting solutions.

The LED controller supports a wide, 5-V to 80-V input/output range for 24-V to 48-V battery systems and delivers flexibility with buck, buck-boost, SEPIC, or boost topologies on each channel. Other features include dual analog dimming pins to enable LED binning and thermal current roll-off using an external NTC, programmable undervoltage current reduction, and spread-spectrum operation combined with 180° phase shifting to help reduce system-level EMI.

The IS32LT3962 is housed in a compact WFQFN-32 package with an exposed pad for enhanced thermal dissipation. The operating temperature range is –40°C to 125°C Automotive Temperature Grade 1.

Lumissil Microsystems’ IS32LT3962 LED controller (Source: Lumissil Microsystems)

Melexis recently announced the launch of the MLX81119, an 18-channel LIN RGB LED controller with an integrated DC/DC converter. This LED controller is designed to simplify and optimize automotive lighting systems.

The MLX81119, housed in a 5 × 5-mm QFN32 package, is powered by Melexis’s 16-bit MCU, with an integrated memory subsystem that includes 32 KB of flash, 13.5 KB of ROM, and 4 KB of RAM to support the application, LED calibration coefficients, and additional system data. It is designed to reduce power dissipation, external components, and space requirements in dense vehicle applications such as door panels, dashboards, and charge port lighting by generating the LED supply voltage locally on the chip.

Simplifying the external power stage, the LED controller operates with as few as two capacitors and a single inductor, eliminating the need for a separate DC/DC controller and associated passives. This design reduces component count and PCB area for more compact lighting modules and easier integration in space-constrained locations.

In conventional architectures, supplying LEDs via external DC/DC converters increases heat generation, component count, and layout complexity, making it harder to meet physical, efficiency, and thermal constraints as automakers increase lighting deployments to meet growing requirements for new functionality, personalization, and brand differentiation, according to Melexis.

The 18-channel MLX81119 addresses these challenges by integrating a 1-A DC/DC converter that generates an optimized local LED supply voltage, programmable between 2.5 V and 6 V. This means the LED controller does not dissipate excess voltage as heat. It dynamically adapts the LED supply to the active color mix and operating conditions to reduce power losses and thermal stress, according to the company, which is not achievable with fixed external DC/DC converter solutions.

The MLX81119 features 18 low-side current sources configurable up to 60 mA and independent 16-bit PWM control. It supports up to six RGB LEDs per device, enabling smooth color transitions and advanced lighting animations, and provides built-in direct and indirect temperature sensing that allows active compensation across all channels, so color points remain stable over the full automotive temperature range.

The MLX81119 integrates a complete LIN system, including transceiver and protocol handler, fully compliant with LIN 2.x and SAE J2602. Developed according to ISO 26262, the device supports up to ASIL-B implementations.

Melexis’s MLX81119 LIN RGB LED controller (Source: Melexis)

Novosense Microelectronics has expanded its portfolio of high-performance LED driver ICs for exterior and interior lighting with several new series. These devices feature high-side and low-side linear drivers, as well as integrated MCU solutions for RGB/RGBW ambient control, and deliver precise current regulation, advanced diagnostics, and robust thermal management for safer, more energy-efficient, and customizable lighting systems.

The lineup includes the NSL21912/16/24 12-, 16-, and 24-channel high-side linear LED drivers, NSL23716x 16-channel low-side linear LED driver, NSL2163x linear LED driver with thermal balancing, and NSUC1500 ambient lighting driver system-on-chip.

The NSL21912/16/24 series devices are automotive high-side LED drivers that deliver 100 mA per channel with 12-bit PWM dimming. They support automatic thermal sharing via VS shunt resistors for higher thermal performance. Other features include configurable LED fault detection, integrated E2PROM for fail-safe functions, a UART interface up to 2 Mbits/s, and optional ASIL-B functional-safety support.

The NSL23716x 16-channel automotive low-side LED driver delivers 100 mA per channel and 12-bit independent PWM dimming. It integrates programmable thermal derating, LED open-/short-circuit detection, and overheat protection with automatic shutdown. It also incorporates built-in OTP memory that supports fail-safe safety functions, and an optional CAN PHY interface eliminates the need for an external transceiver, simplifying design and improving system reliability.

The NSL2163x three-channel automotive linear LED driver provides up to 200 mA per channel and operates directly from a 5-V to 40-V battery supply. The device supports thermal sharing via external shunt resistors and integrates LED open-/short-circuit detection with thermal shutdown for enhanced system reliability. It offers an optional, low-power EN-pin version.

The highly integrated NSUC1500 IC for ambient lighting integrates an Arm Cortex-M3 core and four-channel high-precision current-mode LED drivers. The device provides 16-bit independent PWM dimming and 6-bit analog dimming capabilities. It enables more accurate dimming and color-mixing control while compensating for lumen depreciation, Novosense said. The NSUC1500 is compliant with the AEC-Q100 Grade 1 and CISPR 25 Class 5 EMC standards.

The post Automotive LEDs and drivers: Balancing performance with style appeared first on EDN.