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Non-linear pullup for multi-rate I2C buses

Wed, 05/01/2024 - 17:12

I2C is a popular bidirectional serial communications bus having a clock and a data line. Both line’s drivers consist of an open drain ground-referenced N-channel MOSFET with a pullup resistor connected to a supply ranging from 1.8 V to 5 V. The pullup resistor must be small enough to meet certain timing requirements in the presence of significant bus capacitance, but large enough that the surprisingly weak active driver (specified to drop less than 0.4 V at 3 mA for standard mode and less than 0.6 V at 6 mA for fast mode speeds) current is not exceeded and that the logic low levels are met. Meeting both needs can be a challenge.

Figure 44 in section 7.24 of the UM10204 I2C-bus specification and user manual presents a method of amelioration (Figure 1).

Figure 1: Switched-pullup circuit where the analog switch is activated at high bus voltages only, paralleling an additional resistor with the standard pullup. Source: NXP

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

An analog switch is activated at the higher bus voltages only, paralleling an additional resistor with the standard pullup. This reduces rise time without raising the driver’s achievable logic low level. But when the driver is activated, the amount of improvement is limited by the presence of the additional resistor at the higher voltages—too small an additional pullup, and the allowed driver current will be exceeded, and the required logic low level will not be met. A better approach would be to connect the additional resistor only when the signal is rising, that is, when the driver is off. The driver would then not be fighting the additional pullup, which accordingly could be made extremely small. This is the approach taken with the following circuit.

In Figure 2, comparators U1 and U2 are set to switch at the logic low and high thresholds of a typical 1.8V I2C bus.

Figure 2 A schematic of simulated I2C drivers, pullup resistors and bus capacitances, without (old) and with (new) connection to the autonomous non-linear pullup circuit.

When the driver turns off and releases the signal “new” from a logic low, that signal rises through the low threshold. There is an acceptable propagation-delayed positive output transition of U1 which clocks the 1Q output of D flipflop U3 to a logic high. This activates U4, switching R5 in parallel with the standard pullup R6 and greatly reducing rise time. As the signal rises through the logic high level, the output of U2 transitions to a logic low, clearing the 1Q output of U3, deactivating U4 and disconnecting R5. (In this instance, the propagation delay is welcome. U2’s delay allows the signal time to reach 1.8 V, courtesy of the additional pullup.) The circuit is now ready for the driver’s next activation, which will happen without it having to fight R5. Until activation, the circuit draws negligible current. Figure 3 shows the reduced rise time of the “new” circuit in comparison to that of the “old”, both having the same bus capacitance and same standard pullup. 100 pF is only 25% of the maximum specified value for I2C operation.

Figure 3 A comparison of the performances of standard (old) and an enhanced (new) I2C bus signals. The signals CLR, CLK, and Q swing between ground and +3.3 V are shown scaled for clarity purposes.

Although 1.8 V is a popular bus voltage (especially for smart battery IC’s), I was unable to find suitably fast, adequately low supply current comparators which can be powered from this voltage. Fortunately, 3.3 V is generally available in products with 1.8 V buses, and an analog switch serves admirably to bridge the gap between the two supplies. If the bus runs at 3.3 V, the analog switch can be replaced with a PNP transistor whose emitter is connected to the bus’s supply, and its base driven through a 3.3k resistor. In the unlikely event of a 5 V bus, 5V can be connected to the PNP’s emitter, but a 5 V-supply-capable D flip-flop will need to be found to replace U3.

Christopher Paul has worked in various engineering positions in the communications industry for over 40 years.

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Gated 555 astables can still the ground running even when Vreset doesn’t equal V+

Tue, 04/30/2024 - 17:07

A previous design idea (DI), Gated 555 astable hits the ground running fixed the problem of the excessively long first pulse generated by 555 astables when gated by the RESET pin from oscillation-off to oscillation-on. See Figure 1 and Figure 2.

Figure 1 The problem – first oscillation cycle has a too-long first pulse generated by 555 astables when gated by the RESET pin from oscillation-off to oscillation-on.

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

 Figure 2 The fix via C2 charge injection when Vreset = V+ to equalize pulse length.

 However, unstated in the DI was the simplifying assumption that Vreset = V+ if the C2 = C1/2 fix is to work. But what if they’re not equal?

The LMC555 is rated for V+ supply voltages from 1.5 V to 15 V which lie outside the recommended limits of most logic families. This makes the ability to choose V+ unequal to Vreset a frequently useful thing. Happily, a C2 can still be chosen that will work with most combinations of supply rails. Specifically, the arithmetic is…

  1. Let Ct = total required timing capacitance.
  2. Then C2 = Ct * V+ / Vreset / 3
  3. C1 = Ct – C2

 Some examples:

  1. Vreset = 5v and V+ = 1.5v, C2 = 0.1Ct, C1 = 0.9Ct
  2. Vreset = 3v and V+ = 5v, C2 = 0.2Ct, C1 = 0.8Ct
  3. Vreset = 5v and V+ = 5v, C2 = 0.33Ct, C1 = 0.67Ct
  4. Vreset = 5v and V+ = 15v, C2 = Ct, C1 = 0

 Stephen Woodward’s relationship with EDN’s DI column goes back quite a long way. Over 100 submissions have been accepted since his first contribution back in 1974.

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Lithography specialist ASML decides to stay in Eindhoven, for now

Tue, 04/30/2024 - 13:52

At a time when the semiconductor industry is shrouded in mystery about who is ASML’s second customer of high numerical aperture (NA) extreme ultraviolet (EUV) lithography machine after Intel acquired the first one for its upcoming 14A process node at its fab in Hillsboro, Oregon, ASML has resolved a long-standing matter about its future.

The world’s largest supplier of semiconductor manufacturing equipment has been pondering about moving to another country amid unfavorable business conditions in the Netherlands. Multinationals Shell and Unilever moved their headquarters to London in 2018, citing an unfavorable change in Dutch tax law.

Figure 1 A year after its birth in 1984, ASML moved to a newly built office and factory in Veldhoven, an Eindhoven suburb just a few kilometers from the Philips research labs. Source: ASML

Now ASML—the Netherlands’ largest company and Europe’s largest technology outfit—is having second thoughts due to the government’s immigration policies, housing market shortage, and phasing out of the beneficial tax measures for expats. ASML, which employs 42,000 staff worldwide, has nearly half its workforce based in and around its headquarters in Veldhoven, Netherlands.

It’s important to note that more than 40% of ASML’s 23,000 employees in the Netherlands are not Dutch. In fact, ASML’s initial response was sparked after anti-immigration parties made substantial gains in Netherlands’ 2023 elections. In January 2024, ASML’s then-CEO Peter Wennink warned that his company was highly reliant on skilled foreign labor.

“The consequences of limiting labor migration are large, we need those people to innovate,” he told the press. “If we can’t get those people here, we will go somewhere where we can grow.” That thrust the caretaker cabinet into action, leading to the “Operation Beethoven” initiative to address ASML’s concerns, reported the largest daily newspaper in the Netherlands, De Telegraaf.

The outcome of this government initiative led to a $2.7 billion investment package to improve infrastructure in the Eindhoven region to prevent ASML from moving operations abroad, reported Reuters. The initiative, also aiming to turn Eindhoven into a booming technology hub, will include a large expansion capable of housing 20,000 new employees near Eindhoven’s airport.

The $2.7 billion investment striving to create favorable business conditions for ASML and other Dutch tech outfits will encompass housing, education, transportation, and the electric grid. The infrastructure and highway buildup will also benefit ASML’s headquarters in Veldhoven, a suburb of Eindhoven.

It’s an ambitious undertaking by the Dutch government, and it shows the leverage that successful tech companies have in the socioeconomic context. At the same time, this ambitious expansion plan in Noord-Barbant, an Eindhoven suburb, is merely a letter of intent right now.

That means it’s a long-term undertaking, and that there won’t be any improvements in infrastructure aspects like housing in the short term. “Of course, we have a Plan B, but we want to expand here due to what Veldhoven and Eindhoven have to offer,” said Roger Dassen, ASML’s financial director. “The government also recognizes the circumstances we need to grow.”

Figure 2 The Dutch maker of semiconductor lithography equipment is under immense pressure to maintain its position as an undisputed leader in chip manufacturing gear. Source: ASML

The Dutch paper De Telegraaf, which first reported Operation Beethoven, also mentioned France as a potential destination for ASML’s future expansion. So, while expansion in the Eindhoven region suits ASML because of its existing operations, it has a Plan B in case of failure.

It all comes at a crucial time for the semiconductor lithography titan. It’s nervously charting the opportunity of a lifetime that comes with an unprecedented chip manufacturing boom spanning from Asia to Europe to the United States.

ASML has promptly identified the issues surrounding its future growth, showing its preparedness to fulfill the soaring demand for cutting-edge semiconductor manufacturing equipment. A company spokesperson summed it well by saying that “The decision we need to take is not if we (will) stay, but where we (will) grow.”

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Disclosing the results of a webcam closeup

Mon, 04/29/2024 - 17:24

Remember 2020? Global pandemic lockdown forced many of us out of our cubicles and into haphazard home offices, frantically outfitted and upgraded for their new tasks. Retailer inventories of webcams (and associated green screens), ring lights, microphones, headsets, broadband networking equipment and the like quickly evaporated, boosting the prices of whatever remaining equipment stock scraps were left to stratospheric levels. And both existing and new suppliers, sensing a highly profitable business opportunity, rushed to market with products based on whatever (sometimes subpar) system building blocks they could source.

Four years later, COVID-19 is still with us, of course, but many of us have returned to the cubicles (at least part-time, and sometimes reluctantly). But regardless, we’re now fully gear-equipped at all possible work locations. The electronics supply-vs-demand curve has therefore regained sanity, leading to no-longer-crazy prices. And longstanding webcam (for example) suppliers are differentiating their products, hoping to escape profit-killing commoditization: BenQ with the easily relocatable, macro-capable ideaCam S1 Plus and Pro, for example:

Logitech’s Brio line with a focus (pun intended) on high res and other image enhancements:

And Razer’s Kiyo integrating illumination:

Back to commodities. As I’ve mentioned before, I regularly donate computers, both ones that I’ve personally used and outgrown and others hand-built specifically for this purpose, to a local charity for subsequent handoff to its income- and otherwise-challenged clients. I always make sure that the computers include full online communications capabilities—a microphone, speakers, and a webcam, to be precise—for virtual job interviews, online advanced education classes and the like. With laptops this is easy, since such gear is already built in. For desktop computers, on the other hand, I need to source this stuff separately.

Back in February (as well as several times before, apparently), the Avaya Huddle HC010 Webcam was on sale at bargains site Meh, in this case for $14.99 each. At the time, it was reportedly selling for $60.99 at Amazon (it’s now $39.99 there as I write these words two-plus months later), so I quickly “fished” the three-unit limit (two will eventually end up with charity-donation computers; the third is being dissected here just for you). And longer-term historical data is even more revealing. Back in mid-2021 when the pandemic was still raging and the product was just-introduced, Amazon had it marked at $129 per price-tracking site CamelCamelCamel.

The specs are average and passable:

  • 1080p and 720p resolution options, along with a 30 fps frame rate
  • A/V output: H.264 over USB 2.0
  • Digital (i.e., software-interpolated, and Windows-only) pan, tilt and 4x zoom
  • 85° horizontal field of view
  • Two integrated microphones
  • Built-in privacy cover
  • Integrated activity light
  • Dimensions of 4.65″ (L) x 1.46″ (W) x 1.22″ (H)
  • Weight of 3.28 oz
  • 1/2.8″ CMOS image sensor
  • 8mm focal length

although low-light performance is generally dubious-at-best with such cost-centric products. Here’s a promo video with more details:

And here’s our victim, beginning with the obligatory outer box shots:

Note, to my earlier “suppliers sensing a highly profitable business opportunity” comment, the mid-February 2021 manufacturing date:

Now let’s take a peek inside:

A desiccant packet and two slivers of literature:

Along with (cue striptease music)…

Our patient, as-usual accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for size comparison purposes:

Here’s what it looks like from the front. Note the microphone ports to either side of the currently protected cover/lens, and the currently extinguished activity light above the penny:

Remove the protective sliver of plastic in the center and you can see the privacy cover, marked red to alert you when it’s in place:

versus slid away to reveal the lens behind it:

with both positions controlled by a topside switch:

Here’s the rear (I made a rhyme! I’m easily amused!):

And here’s the bottom, first revealing the ¼” thread tripod base built into the lower segment of the two-piece hinged “foot”:

Unfold the two halves of the “foot” and more product info appears, courtesy of another label (augmenting the already shown one attached to the product packaging):

There’s actually another hinge, this one connecting the “foot” to the main body and convenient for when you need to tilt the webcam down post-mount to more effectively frame the user:

And speak of “mount”, it occurred to me post-disassembly of the Avaya HC010 that some of you might not already be familiar with standalone webcams (versus those built into laptop display bezels) and therefore how they’re mounted to displays. Here’s my woefully dusty Logitech Brio perched on top of my Dell UP2516D two-LCD suite; the HC010 operates similarly:

Onward. The front panel pops off easily:

The translucent rubber piece shown at left in the prior photo fell out as I was pulling the panel off. I put it back in place for the following photo (stay tuned for its function):

We now have our first unobstructed perspective of the insides, once again in both privacy cover-active and-inactive modes:

Note the (inexpensive) electret condenser mics on either side, along with the “hole” into which the other end of the recently mentioned translucent rubber piece fits. The piece’s function, as it turns out, is to act as a sort of “light pipe”, transferring the illumination coming from an embedded-in-hole LED, presumably attached to a PCB-to-be-seen-fully-later, to the front panel.

See, too, those four screws, one in each corner? To proceed further, I first tried removing them:

which didn’t get me anywhere meaningful:

The five additional inner screws, on the other hand…

The aforementioned two-piece “foot” also detached as a result:

Now let’s see if we can get the inside assembly to move:

That’s encouraging:

All that’s left is to detach the USB cable’s power-and-data connector to the PCB:

And out it goes!

with the gasket around each mic coming off in the process:

Here’s a standalone front view of the inner assembly, with most of the PCB still obscured by the black plastic frame:

Top view:


And finally, the now-visible backside:

Four more screws to remove:

And the black plastic frame comes right off. Inside:

Already-seen outside:

And now free-and-clear PCB:

Next, let’s detach those mics:

Note, too, the previously embedded-in-hole LED in the upper left corner of the USB connector:

Bottom-side view:




And now let’s flip the PCB back over and peel off the heat sink you likely already noticed earlier:

The dominant-size square IC now revealed at right has markings too faint to discern in a photo, so you’ll have to take my word that it’s the SSC33x Camera SoC Processor from a company called SigmaStar. The smaller chip in its upper left corner (the one with the dab of blue paint on top of it) is a GigaDevice GD25Q64CSIG 64 Mbit SPI NOR flash memory, presumably containing the system firmware. And in the middle, you probably already noticed two more screw heads:

I’m betting that removing them will enable detach of the lens assembly on the other side of the PCB. Let’s see if I’m right:

Yep, we have liftoff:

Here’s the now-exposed other end of the lens:

And here’s the image sensor!

That wraps it up for today, folks. As always, I welcome your thoughts in the comments!

Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.

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EDA toolset parade at TSMC’s U.S. design symposium

Mon, 04/29/2024 - 15:53

The EDA trio—Cadence Design Systems, Siemens EDA, and Synopsys—is working hands in hand with TSMC to facilitate production-ready EDA tools for the mega-fab’s newest and most advanced processes. These EDA outfits showcased their IC design solutions at the TSMC 2024 North America Technology Symposium held in Santa Clara, California, on 24 April 2024.

The EDA tie-ups with TSMC show how toolmakers have established a symbiotic relationship with large fabs to support chip designers on advanced semiconductor manufacturing nodes. Moreover, it demonstrates why design flow migration is critical when chip designs move from one advanced node to the next.

  1. Cadence

Cadence showcased its node-to-node design migration flow based on the Cadence Virtuoso Studio, which facilitates the migration of schematic cells, parameters, pins, and wiring from one TSMC process node to another. Next, Virtuoso ADE Suite’s simulation and circuit optimization environment tunes and optimizes the new schematic to ensure the design achieves all required specifications and measurements.

That allows IC designers using Cadence tools on TSMC process nodes to automatically recognize and extract groups of devices in an existing layout and apply them to similar groups in the new layout. Cadence has also been working closely with TSMC to ensure its EDA tools’ compatibility with fab’s advanced nodes, including N3E and N2 process technologies.

Figure 1 The enhanced PDKs and EDA methodologies simplify and accelerate the design migration from one process node to another. Source: Cadence

  1. Siemens EDA

Siemens EDA displayed its IC design solutions for TSMC’s latest process and advanced packaging technologies, including IC verification tool Calibre nmPlatform now certified for TSMC’s N2 process. At TSMC’s event, Siemens EDA also demonstrated its FastSPICE platform for circuit verification of nanometer analog, RF, mixed-signal, memory; it’s now certified for TSMC’s N3P, N2 and N2P process nodes.

Figure 2 The EDA toolset certifications are crucial in migration to new IC manufacturing process and advanced packaging technologies. Source: Siemens EDA

Siemens EDA also provided details about collaboration with TSMC to certify its Calibre 3DSTACK solution’s support for the foundry’s latest 3Dblox standard. TSMC’s 3Dblox technology addresses specific IC test and diagnosis challenges that arise at 2-nm geometries and below.

  1. Synopsys

Synopsys also unveiled details about its latest collaborations with the Taiwanese fab, including a co-optimized photonic IC flow, which is integrated with the EDA firm’s 3DIC Compiler and supports TSMC’s 3Dblox technology.

Figure 3 The production-ready design flows were showcased for TSMC’s advanced nodes at the symposium. Source: Synopsys

Additionally, Synopsys showcased its digital and analog design flows compatible with TSMC’s N3/N3P and N2 process nodes. The EDA toolmaker is also working closely with TSMC to ensure the design productivity and optimization of its AI-driven flows such as Synopsys DSO.ai.

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Vibration sensor aids predictive maintenance

Fri, 04/26/2024 - 17:17

Murata’s PKGM-200D-R vibration sensor detects high-frequency vibrations up to 11 kHz to assist predictive maintenance in production equipment. The device measures vibration acceleration along the Z-axis to detect abnormal vibrations, which can indicate early bearing wear and prevent unexpected equipment stoppage.

For rotary bearings, engineers can employ FFT analysis on vibration data to pinpoint irregularities caused by depleted grease or minor surface imperfections. By detecting these anomalies early on, FFT analysis enables proactive intervention, potentially averting impeding issues before they escalate.

Housed in a compact 5.0×5.0×3.5-mm surface-mount package, the PKGM-200D-R integrates a PZT piezoelectric ceramic element, driver circuit, and temperature sensor. Differential analog output reduces line noise. Specifications for the sensor include a detection range of ±10.2 g minimum, a frequency band of 6 kHz to 11 kHz, and sensitivity of 118 mV/g typical.

The PKGM-200D-R vibration sensor requires a supply voltage of 3.0 V to 5.2 V, with current consumption of 3.5 mA. It operates over a temperature range of -20°C to +85°C. The device is now in mass production.

PKGM-200D-R product page 

Murata Manufacturing 

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Generator delivers analog signals up to 40 GHz

Fri, 04/26/2024 - 17:16

A microwave signal generator, the SMB100B from R&S offers four frequency options covering 8 kHz to 12.75 GHz, 20 GHz, 31.8 GHz, and 40 GHz. This midrange analog signal generator provides single sideband (SSB) phase noise of <-106 dBc (measured) at 20 GHz with an offset of 20 kHz and <-100 dBc (measured) at 40 GHz with a 20-kHz offset. According to R&S, the SMB100B also exhibits low wideband noise for all carrier frequencies.

Output power options of 25 dBm at 20 GHz and 19.5 dBm at 40 GHz are activated by keycode and can be installed at any time. In addition to the instrument’s standard OCXO reference oscillator, a high-performance variant is available across all frequency ranges. It enhances close-in phase noise and frequency stability, while reducing sensitivity to temperature variations.

The SMB100B has a standard 10-MHz reference frequency. An optional 1-MHz to 100-MHz variable external reference frequency input allows the unit to be integrated into existing test environments. The received reference frequency can also be sent to a separate reference output. A 1-GHz reference frequency input and output option improves phase stability between multiple SMB100B instruments.

The SMB100B microwave signal generator (up to 40 GHz) is available now and joins the existing RF models (up to 6 GHz).

SMB100B product page

Rohde & Schwarz 

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Gate driver targets 24/48-V automotive market

Fri, 04/26/2024 - 17:16

Tailored for automotive motor control, the TLE9140EQW gate driver from Infineon eases the migration of systems from 12 V to 24 V or 48 V. The IC drives three-phase bridges for brushless DC motors commonly found in automotive applications, such as engine cooling fans, water pumps, oil pumps, and HVAC modules.

Part of the MOTIX family of motor control solutions, the TLE9140EQW gate driver can be paired with Infineon’s MOTIX TLE987x and TLE989x 32-bit motor control MCUs. The driver accommodates a wide input voltage range of 8 Vsm to 72 Vsm and offers high-voltage robustness up to 110 V. It also provides a gate driving capability of ~230 nC/MOSFET up to 20 kHz.

The TLE9140EQW is compliant with the ISO 26262 ASIL B functional safety standard and operates over a temperature range of -40° to +175°C. Protection and diagnostic functions include overvoltage, undervoltage, cross-current, and overtemperature, along with drain-source monitoring and off-state diagnostics.

The TLE9140EQW gate driver is available now in small TS-DSO-32 packages. Infineon also offers an evaluation board to speed prototyping and ease the design-in process.

TLE9140EQW product page

Infineon Technologies 

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LDO regulators provide flexible outputs

Fri, 04/26/2024 - 17:16

ST’s LDH40 and LDQ40 voltage regulators deliver up to 200 mA and 250 mA, respectively, for use in industrial and automotive applications. The LDH40 regulator provides an adjustable output voltage from 1.2 V to 22 V. Variants of the LDQ40 regulator offer either an adjustable output from 1.2 V to 12 V or a fixed output at 1.8 V, 2.5 V, 3.3 V, or 5.0 V. Output voltage tolerance is ±0.5% at 25°C and ±1.5% over temperature.

These two low-dropout (LDO) regulators start up from an input as low as 3.3 V and operate with up to 40 V applied. To help conserve battery energy in always-on standby systems, the devices’ quiescent current is 2 µA at zero load and just 300 nA in logic-controlled shutdown mode. Automotive versions are AEC-Q100 Grade 1 qualified and operate over a temperature range of -40°C to +150°C.

The LDH40 automotive-grade regulator is in production now. Adjustable-output LDQ40 regulators, in industrial and automotive grades, are in production as well. Prices for both the LDH40 and LDQ40 automotive-grade parts start at $0.47 each in lots of 1000 units. Fixed-output LDQ40 automotive components will be available in Q2, with industrial parts to follow in Q3.

LDH40 product page 

LDQ40 product page


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Scope software improves multi-signal analysis

Fri, 04/26/2024 - 17:15

Version 5.4 of SignalVu Spectrum Analyzer software from Tektronix allows multichannel modulation analysis of up to eight signals in parallel. The software transforms Tektronix 5 Series MSO, 6 Series MSO, and DPO70000 oscilloscopes into a comprehensive wireless system tester. This latest update is particularly well-suited for time-domain analysis with RF measurements.

SignalVu Version 5.4 furnishes up to 26 wireless modulation schemes, including 1024-QAM to cater to the demands of higher-bandwidth applications. The introduction of shared-acquisition, multi-signal support enables the simultaneous analysis of signals that are frequency-separated, yet input through the same scope channel. This is important for the validation and optimization of advanced wireless communication systems, including phased array antennas, RF transmitters, and mixed-signal ICs.

SignalVu provides engineers and researchers with in-depth analysis of RF signals. It can be used in a wide range of applications for wireless, military, and government applications, as well as microwave and IoT sectors.

SignalVu Version 5.4 software is available now with a base price of $1670. Digital modulation analysis is offered as a downloadable license (Option SVM).

SignalVu Version 5.4 product page 


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What’s that?…A fuel cell that harvests energy from…dirt?

Fri, 04/26/2024 - 17:10

The continual attraction of energy harvesting is well known. Who can resist possibly getting something—usually electricity—for nothing, or almost nothing? Yet the reality is that in many cases, the harvesting arrangement technically works but its cost in up-front hardware, longevity, actual harvested energy density, or other key metrics versus is an unbalanced, unfavorable situation.

But maybe that’s not a problem in a suitable application scenario. That’s what I found intriguing about a fuel cell developed by a Northwestern University-led team (which included three other universities) that harvests energy from microbes living in plain dirt, Figure 1.

Figure 1 Working in the lab, Northwestern University project leader Bill Yen buries the fuel cell in soil. Source: Northwestern University

The team does not make the usual extremely optimistic claims made by proponents of some other harvesting approaches that their innovative technique is going to “save the planet”. Instead, said Northwestern’s George Wells, a senior author on the study, “These microbes are ubiquitous; they already live in soil everywhere. We can use very simple engineered systems to capture their electricity. We’re not going to power entire cities with this energy. But we can capture minute amounts of energy to fuel practical, low-power applications.”

Where is this scheme a good fit? It’s a natural fit for agricultural IoT situations, where it’s necessary to know soil conditions such as moisture levels and temperature. The obvious solution is solar panels, but they don’t work well in dirty environments because they get covered with dirt, do not work when the sun isn’t out, and take up a significant amount of surface space.

Another option is non-rechargeable batteries, but they have a limited lifetime. It’s not practical to expect farmers to go find these scattered sensor devices to replace that power source.

Use of soil-based microbial fuel cells (SMFCs) is not a new idea, as they have been around since the early 1900s. However, their inconsistent performance and low output power, especially in low-moisture conditions, has impeded attempts to deploy them widely. Nonetheless, as project leader Bill Yen noted, SMFCs offer a large potential advantage (no pun intended), since “As long as there is organic carbon in the soil for the microbes to break down, the fuel cell can potentially last forever.”

How they work

I won’t try to explain the microbiology details, as the research paper does so both briefly and also in detail with the required chemical equations, Figure 2. It says that “In a SMFC, the biofilm growing on the anode oxidizes organic matter to release electrons, which becomes the source of electrical power. The cathode performs a reduction reaction to balance out the cell’s net charge, which requires oxygen as a reactant. The electrolyte facilitates ion exchange between the anode and cathode while preventing oxygen from penetrating into the anode.” That’s a good-enough explanation for me.

Figure 2 The electrochemistry of the microbial-based fuel cell shows how it creates electron flow. Source: Northwestern University

The team set out to overcome the limitations of existing approaches. They designed and tested multiple prototype versions over several years and took the best for literal field tests. That version owes much of its success primary to a new geometry, rather than advanced materials

Instead of using a traditional design, in which the anode and cathode are parallel to each other, that fuel cell used a perpendicular design. It worked well in dry conditions as well as within a water-logged environment.

The anode is made of carbon felt while the cathode is made of an inert, conductive metal and sits vertically on top of the anode; the anode is in the horizontal position while the cathode is at right angles to it, Figure 3.

Figure 3 The physical construction and alignment of the cell’s components is critical to achieving its performance in challenging conditions. Source: Northwestern University

The top end of the anode is buried but flush with the ground’s surface. A 3D-printed cap rests on top of the device to prevent debris from falling inside, while a hole on top and an empty air chamber running alongside the cathode enable consistent airflow.  

Since the lower end of the cathode is relatively deep beneath the surface, it stays hydrated from the moist, surrounding soil—even when the surface soil dries out in the sunlight. After any ground flooding, the vertical design enables the cathode to dry out gradually rather than all at once.

The results of their design were impressive but difficult to compare. The reasons are that there are different ways to assess performance, especially as the output is a function of many varying factors such as moisture level and its timing, temperature, soil type and texture, and more (note there are no defined IEC, ASTM or other standardized tests yet). This dilemma also makes it hard to compare the capabilities of this design to ones done elsewhere. 

One of their many graphs does give some sense of the available output, Figure 4.

Figure 4 One of the may performance graphs shows the small but consistent power output achieved, but there are many varying factors to be considered. Source: Northwestern University

The power level of the cell dropped significantly after it was “transplanted” to the outside. However, it still produced enough power to theoretically turn on MARS during spikes in moisture levels caused by occasional irrigation; see shaded red regions for the energy which can be used by MARS. (Note: MARS is a nano-power battery-free wireless interface developed by other, unrelated researchers in 2021.)

They integrated their design with an RF-backscatter scheme to transmit sensor data in SMFC-powered system, Figure 5. Backscatter operates on the order of nanowatts, making them suitable for SMFC-powered applications. By using a purely analog backscatter device like MARS, they achieved superior performance in terms of runtime availability and robustness without using batteries and storage capacitors.

Figure 5 By combining the SFMC with an RF-backscatter scheme, they were able to build and test a complete sensor and data-reporting module. Source: Northwestern University

How much more improved is their design compared to other efforts? Short answer: it’s very hard to say, primarily due to lack of a standard test procedure as noted. However, they did report they felt the data showed it was an impressive ten to 50 times better.

Also impressive is their published paper, “Soil-Powered Computing: The Engineer’s Guide to Practical Soil Microbial Fuel Cell Design” (at the Proceedings of the Association for Computing Machinery on Interactive, Mobile, Wearable and Ubiquitous Technologies). At 40 pages, it is the longest academic-class paper I have ever seen, and for good reason.

How so? It is not just a report on what they did and the results. Instead, it’s really a complete design course. It discusses how they designed, built, and evaluated various versions until they reached their final one. It also explains how they identified the shortcomings of each version, and the flow-chart they devised for each observed problem as they methodically approached each, strived to identify one or more causes, and then minimized the problem. As a result, the paper is a comprehensive tutorial in the realities of a total project cycle, even if the result is not a commercially abatable device as is the case here.

What’s your view on the practicality of microbe and soil-based harvesting for these field applications? Have you even been attracted to energy-harvesting designs which appear to have significant capabilities, until you looked more closely at the realities of their implementation?

Bill Schweber is an EE who has written three textbooks, hundreds of technical articles, opinion columns, and product features.

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Universal analog-to-digital multiplexer-demultiplexer

Thu, 04/25/2024 - 16:40

The possibility of creating a universal analog-to-digital multiplexer-demultiplexer is shown.

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

As is known, a multiplexer and a demultiplexer is an electronic device designed for selective signal transmission from one of several inputs to one output, or, on the contrary, signal transmission from one input to one of several outputs. Channel switching is performed by digital signals supplied to the control inputs.

First, let’s consider the operation of a control node containing key elements controlled by digital input signals. Figure 1 shows an example of such a node based on discrete elements such as bipolar or field-effect transistors; or using two “NOT” logic elements. When applying to the input (Inp) of such a node, signals of the level “Log. 1»/«Log. 0” the output signal levels Out1 and Out2 are switched. To switch, for example, four channels, it is necessary to use two similar control nodes.

Figure 1 Control node using discrete elements such as bipolar or field-effect transistors.

Figure 2 shows the electrical circuit of the signal transmission channel switching unit, made using two control units, Figure 1, as well as diode-resistive elements. The signals from the ABCD outputs are sent to the corresponding ABCD control inputs of analog switches, Figure 2.

Figure 2 Electrical diagram of the analog switch control unit using discrete elements.

When digital signals of the level “Log. 1” or “Log. 0” are applied to the inputs, X1 and/or X2 of the control nodes implements four combinations of selective appearance at the outputs of the ABCD levels “Log. 1”. The inputs and outputs of analog switches have the property of reversibility, which allows the device to be used both as a multiplexer and a demultiplexer.

Figure 3 shows a variant of the control unit for analog switches from a set of logic elements “NOT” and “2AND”.


Figures 3 Electrical diagram of the analog switch control unit using logic elements.

To be able to disable the passage of any signals from the input to the output of the device, or vice versa, the scheme shown in Figure 2 can be supplemented with the function of general disconnection of the passage of signals, Figure 4. When an Inhibit signal of the “Log. 1” level is applied to the input, the transistor Q opens and shunts the control inputs of the analog switches ABCD through the diodes.

Figures 4 Electrical diagram of the device for general disconnection of signals passing through all switching channels.

Figure 5 shows the possible pin arrangement of the universal analog multiplexer/demultiplexer chip, its schematic representation, and truth table.

Figure 5 Possible pin layout of the universal analog multiplexer/demultiplexer chip, its schematic representation, and the truth table.

Figure 6 demonstrates the possibility of using such a device as a multiplexer when signals from 4 sources are fed to the ABCD inputs. When digital control signals are applied to inputs X1 and X2, one of the signals taken from sources E1–E4 will pass to the output Y of the device.

Figure 6 Using a universal analog multiplexer/demultiplexer as a multiplexer, its graphical designation, equivalent circuit, and truth table.

Figure 7 shows the options for using a universal analog of a universal multiplexer/demultiplexer as a demultiplexer.

Figure 7 Using a universal analog multiplexer/demultiplexer as a demultiplexer, its graphical designation, equivalent circuit, and truth table.

Figure 8 shows an example of using a device for selectively enabling/disabling information transmission channels from sources E1–E4 to the outputs/inputs of ABCD.

Figure 8 Examples of using a universal analog multiplexer/demultiplexer to control the passage of signals through one of the channels involved.

The described device can be used for switching both analog and digital signals of positive polarity, however, with a slight improvement of the device, it can be converted to switch signals of both positive and negative polarity.

Michael A. Shustov is a doctor of technical sciences, candidate of chemical sciences and the author of over 800 printed works in the field of electronics, chemistry, physics, geology, medicine, and history.

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5 considerations when choosing a haptics manufacturer

Thu, 04/25/2024 - 10:21

In the rapidly emerging world of haptic technology, businesses are increasingly recognizing the value of integrating haptic feedback into their products. In a study conducted by Immersion Corp. on consumer attitudes about high-definition haptic effects in smartphones, a vast majority of respondents (~90%) said they prefer mobile phones that offer haptic feedback. Another study from the University of Oxford found that the participants performed tasks better when notifications came with haptic feedback.

This shows that haptics is poised to play a big role in shaping user perceptions and behaviors. Market research firm CB Insights projects that the haptics industry is projected to grow at a CAGR of 3.7%, reaching a value of $ 5 billion by 2028. Moreover, a gradual shift toward touch-centric consumer gadgets is paving the way for more opportunities in haptic technology.

Source: Titan Haptics

Integrating haptics into your next product comes with a plethora of benefits. It not only enhances the user experience, leading to improved brand image and customer satisfaction, but can also boost accessibility, safety, and precision. Additionally, haptics can enable businesses to offer customization options, future-proof their offerings, and explore new revenue streams.

That said, the manufacturing of haptic products is no small feat. It requires a blend of multidisciplinary expertise, careful consideration of user experience, seamless integration of technology, meticulous material selection, and strategic planning for scalability.

What are the issues to think about when manufacturing haptic products?

  1. Multidisciplinary expertise

Haptic technology is a complex field that requires a deep understanding of electronics, firmware, software, and mechanical engineering. For small- to medium-sized enterprises (SMEs), this multidisciplinary nature can pose a significant challenge.

Consider a startup that specializes in virtual reality (VR) gaming and wants to incorporate haptic technology into its products to enhance user experience. This startup may have a team of software engineers who are proficient in developing VR games but lack the expertise in haptic technology.

In order to incorporate their desired haptics, a partnership with a full-service manufacturer or product development firm may be beneficial. This can help bridge the necessary expertise in electronics, firmware, software, and mechanical engineering. As a result, the startup can focus on its core competency, while ensuring that its products are enhanced with the latest haptic technology.

  1. User experience (UX)

The user experience (UX) should be a priority when designing haptic products. The haptic feedback should be instinctive and enhance the user’s engagement with the product. However, the transition from prototype to mass production may introduce changes that could impact the intended user experience.

This is where a manufacturer with expertise in manufacturing haptic products becomes invaluable. Manufacturers can recommend vibration damping to significantly enhance the haptic feedback. They can also procure high-quality components like buttons—loose buttons that create noise during haptic feedback can negatively impact the user experience.

Manufacturers can also tailor the product to its intended use. For instance, if the product is designed for use in a heavy-duty industry, the motors need to be sealed against environmental factors. This ensures they are not compromised by dust and debris, thereby maintaining the quality of the haptic feedback and, in turn, the user experience.

  1. Material selection

The choice of materials in the production of haptic products can significantly influence the quality of the haptic feedback. Selecting the appropriate materials is a vital part of manufacturing haptic products, as an unsuitable choice can negatively impact the product’s functionality and effectiveness.

For example, using a rigid material for a haptic glove, which needs high touch sensitivity and responsiveness, may not deliver the subtle haptic feedback required for an immersive virtual reality gaming or medical training experience.

The importance of material selection goes beyond the product’s performance. It also impacts user comfort, market attractiveness, and, ultimately, sales. Experienced haptic product manufacturers can provide insight and suggest suitable materials for the product’s intended use. They can also assist companies in making educated decisions regarding material selection, which also has an impact on cost.

  1. Scalability

In addition to the technical considerations, it’s also important to consider the scalability of a product. This involves consideration of manufacturing processes, cost, and quality control measures. A well-thought-out design should be scalable for mass production without compromising on quality.

Scalability in manufacturing is a crucial factor in effectively boosting production volumes to satisfy rising market needs while keeping or even reducing costs per unit. Imagine a startup that has created a new high-definition haptic gaming controller. At first, production is on a small scale, with only a few hundred units produced each month. However, as the product becomes more popular, demand surges.

With this increased demand, there are additional factors to consider. While producing more units could decrease the cost per unit due to economies of scale, it could also inflate total costs if not properly managed.

Therefore, it’s crucial to collaborate with a trusted manufacturer to ensure that the quality of the product aligns with the company’s standards, values, and customer expectations.

  1. Importance of IP protection

In the tech-driven haptic industry, intellectual property (IP) is a critical asset. Protecting this asset can be a complex and challenging process, particularly when dealing with international suppliers. A robust IP protection plan is critical in providing peace of mind for a business.

Consider a company that has developed a unique haptic feedback mechanism for a wearable. This mechanism could be a huge differentiating factor that sets the product apart from similar wearable devices. However, without a solid IP protection plan, the company risks losing its competitive edge if the mechanism is copied or reverse-engineered by a rival.

This risk is particularly high when dealing with international suppliers, as different countries have different laws and regulations regarding intellectual property. For example, if the company is sourcing components from China, it needs to be aware of the Chinese laws on intellectual property and ensure that its IP protection plan is robust enough to protect its technology.

Why a qualified manufacturing partner matters

Manufacturing haptic products can be incredibly challenging and requires careful consideration of the factors outlined above. A qualified manufacturing partner should be capable of addressing all these factors and offering advice on how haptic products can be optimized for their use case.

By understanding these complexities and partnering with a reliable manufacturing program, businesses can successfully navigate the haptic industry and create products that deliver value to their customers.

Kyle Skippon is head of engineering at Titan Haptics Inc.

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Sidereal time versus solar time

Wed, 04/24/2024 - 15:56

About time keeping, the definition of “sidereal” is “of or with respect to the distant stars (i.e. the constellations or the fixed stars, not the sun or planets)”, as defined after a google search. With that in mind, a quick and admittedly simplistic look at keeping earthly time is shown in Figure 1.


Figure 1 A comparison between solar days of 24 hours and sidereal days of 23 hours, 56 minutes, and 4.091 seconds.

As the earth moves around the sun in its yearly orbit, the absolute direction in which some fixed point on the earth’s surface that is aimed directly at the sun changes. We who sit on the earth at some particular place, maybe in our backyards, see the sun reach its peak in the sky once every twenty-four hours and we call that a solar day. Disregarding leap years, leap seconds, and the like; our wristwatches, tabletop alarm clocks, and other timepieces keep track of our personal time on a solar day basis.

Measured with respect to absolute space, however, the solar day requires an earth rotation per “day” of slightly more than 360°. Thus, when we take the universe at large as some fixed entity, with respect to that entity, the earth completes an exact 360° rotation in an average time of only 23 Hours, 56 Minutes, 4.091 Seconds which is a shorter time span.

That shorter time span is a sidereal day which differs from and is slightly less than a solar day.

Have you checked your watch lately?

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

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Power Tips #128: Designing a high voltage DC-link capacitor active precharge circuit

Tue, 04/23/2024 - 18:41


Electric vehicles (EVs) typically feature a large DC link capacitor (CDC LINK) to minimize voltage ripple at the input of the traction inverter. When powering up an EV, the purpose of precharging is to safely charge up CDC LINK before operating the vehicle. Charging CDC LINK up to the battery stack voltage (VBATT) prevents arcing on the contactor terminals, which can lead to catastrophic failures over time.

The conventional precharge method involves implementing a power resistor in series with the CDC LINK to create a resistor-capacitor (RC) network. However, as the total CDC LINK capacitance and VBATT increase, the required power dissipation grows exponentially. In this article, we’ll present a straightforward approach to designing an efficient, active pre-charge circuit using a spreadsheet calculator.

Understanding active precharge

While passive precharge employs a power resistor to create an RC circuit that charges the capacitor asymptotically, active precharge can employ a switching converter with a buck topology that uses hysteretic inductor current control to deliver a constant charge current to the capacitor (Figure 1).

Figure 1 The active precharge circuit where a buck converter uses a hysteretic inductor current control to deliver a constant charge current to the capacitor to enable the linear charge of the capacitor voltage (VCAP) up to the same voltage potential as the battery (VBATT). Source: Texas Instruments

This constant current enables linear charging of the capacitor voltage (VCAP) up to the same voltage potential as that of the battery. Figure 2 and Equation 1 characterize this linear behavior.

Figure 2 Active precharge linear behavior using a buck topology with hysteretic inductor current control. Source: Texas Instruments

The first step is to determine the required charge current (ICHARGE). ICHARGE is the quotient of the total DC link charge (QDC LINK) and the required precharge time (tCHARGE) shown in Equation 2.

QDC LINK is the product of CDC LINK and VBATT, as shown in Equation 3.

Calculator overview

This active hysteretic buck circuit has a floating ground potential riding on the switch node, so powering the control system requires an isolated bias supply. The calculator tool will ensure that the power consumption of this control circuitry stays within the sourcing capability of the isolated bias supply, or else the voltage will collapse.

The High-Voltage Solid-State Relay Active Precharge Reference Design from Texas Instruments (TI) introduces an active solution that enhances energy transfer efficiency and reduces practical charge time. TI’s TPSI3052-Q1 is a fully integrated isolated bias supply used in the active precharge reference design, which can source and supply up to 83 mW of power to the isolated secondary. Gate drive current, device quiescent currents, and resistor dividers are the primary contributors to power consumption. Equation 4 characterizes the gate drive power (PGATE DRIVE) as the product of the gate drive current (IGATE DRIVE) and gate drive voltage (VS GATE DRIVER) which is 15 V, in the case of the reference design.

Equation 5 characterizes gate drive current as the product of the metal-oxide semiconductor field-effect transistor (MOSFET) total gate charge (QG) and switching frequency (FSW).

Equation 6 expresses how FSW varies according to VCAP throughout the charging period, creating the upside-down parabola in the FSW versus VCAP curve in Figure 3. As shown in the Figure, the gate drive current peaks at the maximum switching frequency (FSW_MAX), which occurs when VCAP reaches half of VBATT. Equation 7 expresses the relationship between FSW_MAX, VBATT, inductance (L) and peak-to-peak inductor current (dI):

Figure 3 Calculator curve showing FSW versus VCAP and FSW LIMIT. Source: Texas Instruments

Using the calculator tool

The calculator prompts you to input various design parameters. The yellow cells are the required inputs while gray cells signify optional inputs. The default values in the gray cells reflect the parameters of the reference design. A user can change the gray cell values as needed. The white cells show the calculated values as outputs. A red triangle in the upper-right corner of a cell indicates an error; users will be able to see a pop-up text on how to fix them. The objective is to achieve a successful configuration with no red cells. This can be an iterative process where users can hover their mouse over each of the unit cells to read explanatory information.

Precharge system requirements

The first section of the calculator, shown in Figure 4, computes the required charge current
(ICHARGE REQUIRED) based on the VBATT, tCHARGE, and CDC LINK system parameters.

Figure 4 The required charge current (ICHARGE REQUIRED) based on the VBATT, tCHARGE, and CDC LINK system parameters. Source: Texas Instruments

Inductance and charge current programming

The section of the calculator shown in Figure 5 calculates the actual average charging current (ICHARGE) and FSW_MAX. The average inductor current essentially equates to ICHARGE where ICHARGE must be equal to or greater than ICHARGE REQUIRED, this was calculated in the previous section to meet the desired tCHARGE.

Be mindful of the relationship between L, dI, and FSW_MAX as expressed in Equation 7. L and dI are each inversely proportional to FSW, so it is important to select values that do not exceed the maximum switching frequency limit (FSW LIMIT). Your inductor selection should accommodate adequate root-mean-square current (IRMS > ICHARGE), saturation current (ISAT > IL PEAK), and voltage ratings, with enough headroom as a buffer for each.

Figure 5 Inductance and charge current programming parameters. Source: Texas Instruments

 Current sensing and comparator setpoints

The section of the calculator shown in Figure 6 calculates the bottom resistance (RB), top resistance (RT), and hysteresis resistance (RH) around the hysteresis circuit needed to meet the peak (IL PEAK) and valley (IL VALLEY) inductor current thresholds specified in the previous section. Input the current sense resistance (RSENSE) and RB. These are flexible and can be changed as needed. Make sure that the comparator supply voltage (VS COMPARATOR) is correct.

Figure 6 Section that calculates the bottom resistance (RB), top resistance (RT), and hysteresis resistance (RH) around the hysteresis circuit needed to meet the peak (IL PEAK) and valley (IL VALLEY) inductor current thresholds. Source: Texas Instruments

Bias supply and switching frequency limitations

The section of the calculator shown in Figure 7 calculates the power available for switching the MOSFET (PREMAINING FOR FET DRIVE), by first calculating the total power draw (PTOTAL) associated with the hysteresis circuit resistors (PCOMP. RESISTORS), the gate driver integrated circuit (IC) (PGATE DRIVER IC), and the comparator IC (PCOMPARATOR IC), and subtracting it from the maximum available power of the TPSI3052-Q1 (PMAX_ISOLATED BIAS SUPPLY). Input the MOSFET total gate charge (QG TOTAL), device quiescent currents (IS GATE DRIVER IC and ISUPPLY COMP IC), and gate driver IC supply voltage (VS GATE DRIVER IC). The tool uses these inputs to calculate FSW LIMIT displayed as a red line in Figure 3.

Figure 7 Isolated bias supply and switching frequency limitations parameters. Source: Texas Instruments

The calculator tool makes certain assumptions and do not account for factors such as comparator delays and power losses in both the MOSFET and the freewheeling diode. The tool assumes the use of rail-to-rail input and output comparators. Make sure to select a MOSFET with an appropriate voltage rating, RDSON, and parasitic capacitance parameters. Ensure the power loss in both the MOSFET and freewheeling diode are within acceptable limits. Finally, select a comparator with low offset and low hysteresis voltages with respect to the current sense peak and valley-level voltages. Simulating the circuit with the final calculator values ensures the intended operation.

Achieved the desired charge profile

Adopting an active hysteretic buck circuit significantly improves efficiency and reduces the size of the charging circuitry in high voltage DC-link capacitors found in EVs. This helps potentially lower the size, cost, and thermals of a precharge solution.

This article presents the design process to calculate the appropriate component values that help achieve the desired charge profile.

By embracing these techniques and tools, engineers can effectively improve the precharge functionality in EVs, leading to improved power management systems to meet the increasing demands of the automotive industry.

Tilden Chen works as an Applications Engineer for the Texas Instruments Solid State Relays team, where he provides product support and generates technical collateral to help win business opportunities. Tilden joined TI in 2021 after graduating from Iowa State University with a B.S. in Electrical Engineering. Outside of work, Tilden enjoys participating in Brazilian jiu-jitsu and shuffle dancing.

 Hrag Kasparian, who joined Texas Instruments over 10 years ago, currently serves as a power applications engineer, designing custom dc-dc switch-mode power supplies. Previously, he worked on development of battery packs, chargers, and electric vehicle (EV) battery management systems at a startup company in Silicon Valley. Hrag graduated from San Jose State University with a bachelor of science in electrical engineering.

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Palladium emulation: Nvidia’s Jensen Huang is a fan

Mon, 04/22/2024 - 17:39

Nvidia CEO Jensen Huang calls Palladium the only appliance more important to him than the refrigerator. At Cadence Design Systems annual event in Santa Clara, California, he also acknowledged that Nvidia has the largest installation of Palladium emulation systems.

Earlier, during a fireside chat, Huang said that Blackwell AI processor would not exist without Palladium. So, what’s Palladium and why is it making waves for large and powerful chip designs? It’s an emulation tool built around Cadence’s custom processors, and it’s used for pre-silicon hardware debugging.

Figure 1 Palladium Z3 and Protium X3 deliver fast pre-silicon verification and validation of the large, complex chip designs. Source: Cadence

At CadenceLive, held on 17 April 2024, the EDA toolmaker unveiled Palladium Z3 alongside Protium X3. “The supercharged Palladium Z3 and Protium X3 are built to deliver fast pre-silicon verification and validation of the largest and most complex devices,” said Dhiraj Goswami, corporate VP of hardware system verification R&D at Cadence.

Palladium Z3, which offers approximately 1.5 times the performance of its predecessor Palladium Z2, can scale from 16 million gates to all the way 48 billion gates. It also features specialized apps for tasks such as 4-state emulation, mixed-signal emulation, safety emulation, and fine-grained power analysis.

Next, the Protium X3 system, built around AMD Epyc processors paired to AMD Versal Premium VP1902 adaptive system-on-chips (SoCs), provides physical prototyping to accelerate bring-up times for pre-silicon software validation of complex, multi-billion gate chip designs. It’s also 1.5 times faster than its predecessor, Protium X2.

Palladium and Protium create a virtual version of a chip to start writing software while waiting for the physical chip to return from the fab. That’s how chip design emulation accelerates time to market. However, though Palladium Z3 and Protium X3 work in tandem, as explained above, they facilitate different types of workloads.

Figure 2 Palladium Z3 and Protium X3 feature a unified compiler and common virtual and physical interfaces. Source: Cadence

Nvidia, which used Palladium Z3 and Protium X3 predecessors in designing just-announced Blackwell AI processors, is already testing these upgraded systems in some of its AI processor designs. “The next-generation Palladium and Protium systems push the boundaries of capacity and performance to help enable a new era of generative AI computing,” said Scot Schultz, senior director for networking at Nvidia.

Today’s large chip designs serving applications like AI and high-performance computing (HPC) increasingly demand emulation solutions that offer higher performance along with faster and more predictable compile debug. New emulation systems such as Palladium fill the need with early software development, hardware-software verification, and debug tasks.

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USB activation dongles: Counterfeit woes

Mon, 04/22/2024 - 17:27

My Blackmagic Design video cameras are compatible with numerous editing software packages, but the company’s own DaVinci Resolve is a particularly compelling option. For one thing, there’s a close-knit synergy—or at least the natural potential for one—whenever the hardware and software come from the same company. DaVinci Resolve, for example, is able to access the camera’s gyroscope-generated metadata in order to implement post-capture stabilization of video footage; an admittedly inferior alternative to the in-body stabilization (IBIS) offered by competitors’ cameras, which operates during initial footage capture, but better than nothing.

The baseline DaVinci Resolve suite is also completely free, and robustly featured to boot. That said, Blackmagic’s cameras come bundled (at least from the factory…this is something often in-advance stripped out of used units offered for resale) with license keys for the paid DaVinci Resolve Studio variant, which offers some key enhancements for more advanced videography use cases. Each license key allows for two concurrent-use “seats”, and deactivating (at least temporarily) one installation associated with your key and account in order to activate another is straightforward…but it requires a “live” Internet connection to Blackmagic’s server farm, which may not be feasible if you’re “in the field” at the time.

Alternatively, therefore, the company also sells (through its various retail partners) USB activation dongles. Here’s an example, from Sweetwater’s site:

As you can see, they cost the same as a software license key: $295, which is a bit “salty”, both absolutely and relative to “free”. But last May, shortly after buying my two cameras (only one of which came with a key), I came across a claimed “used” one on eBay for just over $100. For the flexibility of two additional concurrent active “seats”, if no other reason, I took the plunge.

When the dongle arrived (from a Vietnam-based seller, it turns out, contrary to the upfront U.S.-sourced claim, and which in retrospect should have been my first warning sign), the packaging was admittedly a bit sketchy:

But the dongle itself looked legit, at least at initial quick glance (as-usual accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for size comparison purposes):

And it was recognized by both MacOS and Windows systems, along with (at least at the time, keep reading) correctly activating DaVinci Resolve Studio installs on both O/Ss:

(keen-eyed readers will notice that I’ve gone ahead and added the Satechi hub to the Mac mini “stack” covered in one of last month’s blog posts, to give me easy front-panel access to various interface and expansion connectors)

More recently, however, I decided to update my various DaVinci Resolve Studio “seats” to latest-version 18.6. Afterwards, my ability to continue activating them via the dongle abruptly ceased. Jumping on Google, I learned that I wasn’t alone in my dismay (not to mention its root cause):

Like some previous releases we also have blocked some dongle key ids that are counterfeit. If you purchased second hand or not from an authorized reseller you may have one of those.

Unsurprisingly, the original seller (whose eBay account is still active as I write these words; note, too, that the seeming same person(s) was/were also selling “used” dongles on Amazon at the same time I bought mine on eBay) hasn’t responded to my outreach. That said, I give eBay plenty of kudos; the rep to whom I reported the issue promptly issued me a future-purchase coupon for the full amount.

But I was still curious to see what else I could find out about this forgery. I’ll probably eventually do a proper teardown, so stay tuned for that, although note that I’m not going to also drop $300 on a legit one for comparison purposes (!!!). For now, I’ll share some screenshots of how the dongle self-identifies to both MacOS:                                           


and Windows:

I’m pretty sure the first time I heard the adage “if it sounds too good to be true, it probably is” was as a child, and came from my parents. Decades later, the wisdom still applies. Caveat emptor, folks! Sound off with your thoughts in the comments.

Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.

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Actuation gear aids aircraft electrification

Fri, 04/19/2024 - 18:09

Microchip has combined gate driver boards with its Hybrid Power Drive (HPD) modules to ease the aviation industry’s transition to electric actuation systems. Configured with silicon or silicon carbide switches, the HPD modules cover a range of 5 kVA to 20 kVA and maintain the same footprint regardless of the power output.

These integrated actuation power bundles provide a plug-and-play motor drive solution for the electrification of such systems as flight controls, braking, and landing gear. Power components are designed to scale based on application requirements. They can be used to create actuation systems for drones, small planes, electric vertical take-off and landing aircraft, More Electric Aircraft (MEA), and all-electric aircraft.

Gate driver boards are driven with external PWM signals. They provide differential outputs for telemetry signals like DC bus current, phase current, and solenoid current by taking feedback from shunts in the HPD modules and DC bus voltage. The isolated boards operate over a temperature range of -55°C to +110°C and require a single 15-VDC input for the control and drive circuit. Additional required voltages can be generated on the card.

The gate driver boards and accompanying HPD modules are available now in production quantities. To learn more about these integrated actuation power components, click here.

Microchip Technology 

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7-A switch protects USB-C connections

Fri, 04/19/2024 - 18:08

The AOZ1377DI current-limiting switch from Alpha & Omega improves USB-C safety by providing a maximum load current of 7 A at up to 23 V. In addition to programmable current limiting, the switch offers true reverse current blocking, which prevents unwanted reverse current from flowing from VOUT to VIN.

Useful for both sink and source applications, the AOZ13771DI has an input operating voltage range of 3.4 V to 23 V. Both VIN and VOUT terminals are rated at an absolute maximum of 28 V. Integrated back-to-back N-channel MOSFETs provide a typical on-resistance of 19 mΩ and a high safe operating area. In addition, an internal soft-start circuit controls inrush current from high capacitive loads, and an external capacitor can adjust the slew rate.

The protection switch comes in two variants. The AOZ1377DI-01 automatically restarts once fault conditions are cleared. The AOZ1377DI-02 latches the power switch off, and the enable-input pin must be reset to restart the device.

The AOZ1377DI-01 and AOZ1377DI-02 switches cost $1.356 in lots of 1000 units. They are available in production quantities with a lead time of 16 weeks

AOZ1377DI datasheet

Alpha & Omega Semiconductor 

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32-bit MCUs pack ample memory and resources

Fri, 04/19/2024 - 18:08

Microcontrollers in the GD32F5 series from GigaDevice are equipped with 7.5 Mbytes of on-chip flash and 1 Mbyte of SRAM, both supporting ECC verification. Up to 2 Mbytes of code flash can be configured for zero-wait-state operation, improving processing speed and efficiency. A maximum of 2 Mbytes of memory is also available for read-while-write OTA updating. Additionally, the MCUs accommodate a variety of external memories.

The GD32F5 series of MCUs is based on an Arm Cortex-M33 processor. This 32-bit core operates at up to 200 MHz and delivers a performance rating of 3.31 CoreMark/MHz. An integrated 12-bit successive approximation ADC module can sample analog signals from 16 external channels and 2 internal channels, plus the battery voltage channel. MCUs also feature two DACs and multiple timers. Connectivity resources include UART/USART, I2C, SPI, I2S, SDIO, USB, CAN-FD, and Ethernet.

A set of built-in system security features offers protection for both firmware and device private data, as well as service execution assurance. The general-purpose MCUs operate with a supply voltage of 1.71 V to 3.6 V and have 5-V tolerant I/Os. The lineup comprises 10 variants in a choice of packages, including BGA and LQFP.

GD32F5 series product page 


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