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In the realm of advanced electronics and photonics, compound semiconductors are the silent enablers of breakthrough performance in many applications. Built from materials like indium gallium arsenide (InGaAs) or gallium arsenide (GaAs), these semiconductors enable applications that are beyond the capabilities of silicon devices.

Examples include avalanche photodiodes (APDs) for ultra-sensitive infrared detection at eye-safe wavelengths. These are used in LiDAR, optical test equipment, optical communications, and laser range finders, for example.

But as useful as they are, APDs made from compound semiconductors have some vulnerabilities, all of which can be mitigated through careful storage, handling, and application. Handle them with care, and you will avoid compromised performance, reduced lifespan, or complete failure.

Here’s what you need to know to ensure these components give their best.

Figure 1 Compound semiconductors have unique characteristics that can lead to vulnerabilities, but all of these can be mitigated with appropriate storage, handling, and application. Source: Phlux Technology

Why compound semiconductors are more fragile than silicon

Compared to silicon, compound semiconductors are physically and chemically more delicate. Their crystal structure makes them brittle, so they’re more likely to crack or chip if dropped or mishandled. Chemically, they’re also more reactive, exposing them to moisture, dust, or skin oils can lead to surface degradation, which affects performance.

They also struggle with heat. Lower thermal conductivity and mismatched coefficients of expansion make them vulnerable to thermal shock. Moreover, poor soldering practices or rapid temperature changes can cause delamination or internal fractures. And because many compound semiconductor APDs operate at low voltages and high impedance, they’re exceptionally sensitive to electrostatic discharge (ESD). A tiny static zap, invisible to you, might silently destroy the device.

APDs: Your handling survival guide

1. Watch out for static

ESD isn’t just a nuisance, it’s a silent killer. Always handle APDs in an ESD-safe environment. That includes grounded workbenches, wrist straps, anti-static mats, and maintaining relative humidity between 40–60% to prevent static buildup. Keep the devices in anti-static packaging until you’re ready to use them.

2. Handle with a gentle touch

APDs are inherently a little fragile. Use appropriate tools such as tweezers or vacuum pickups and handle the correct areas: the can for TO-CAN packages, the edges for SMDs, and the ferrule (never the fiber) for fiber-pigtailed versions. Never apply pressure to the photosensitive area or exposed wire bonds.

Contamination, whether from skin oils or airborne particles, can degrade signal integrity, so wear gloves and work in cleanroom or semi-clean environments. If cleaning is necessary, use approved solvents or dry nitrogen with extreme care.

3. Beware the heat

Thermal stress is one of the top killers of compound semiconductors. Always follow recommended soldering profiles using gradual temperature ramps to prevent cracking or delamination. Preheat boards before reflow soldering and allow cooling to happen slowly. Desoldering is especially risky because temperatures above 330°C, even for just a few seconds, can irreparably damage many APD packages.

4. Store them smart

APDs are sensitive even when idle. Store them between 5°C and 30°C, with relative humidity below 60%. Use moisture-barrier bags with desiccant packs and humidity indicators whenever possible. If you remove them from their original packaging, ensure the alternative provides equivalent ESD and moisture protection.

For SMD APDs, pay close attention to their moisture sensitivity level (MSL). Devices stored for extended periods—especially over a year—should be visually inspected and electrically tested before use. And if the MSL safe exposure window has been exceeded, follow proper bake-out procedures before reflow soldering.

Package-specific recommendations

1. TO-CAN APDs

These are relatively robust but not invincible. The transparent window is critical for light transmission and must be kept clean and scratch-free. Avoid applying excessive mechanical force to the can, and ensure mounting solutions (sockets, clips, or heat sinks) don’t stress the package. Good thermal management is especially important when operating at high optical power or bias voltage.

Figure 2 Even TO-CAN packaged APDs need careful handling, so it’s important to keep transparent windows clean and scratch-free. Source: Phlux Technology

2. SMD APDs

These are compact and efficient, but they come with stricter handling requirements. Many come under MSL 2 or MSL 3 classifications, meaning they must be soldered within a limited time after exposure to air. If that window closes, you’ll need to bake them before soldering. Stick to soldering temperatures between 270–300°C and avoid brief spikes above 330°C.

3. Fiber-pigtailed APDs

These versions come with an optical fiber attached, and the fiber is the most delicate part of the assembly. Never bend it below its minimum bend radius and always protect the end-face with a dust cap or ferrule cover. Even minor contamination at the tip can cause significant optical loss or permanent damage.

Best practices summary

• Use strict ESD precautions at every stage of handling.
• Avoid mechanical shocks, bending, or applying pressure in the wrong places.
• Store APDs in controlled temperature and humidity environments with proper packaging.
• Follow soldering guidelines carefully, including reflow and desoldering profiles.
• Keep optical fibers clean and protected from strain or contamination.

APDs built from compound semiconductors are extraordinary components and enablers of much of the technology we take for granted today. However, they also require more attention than their silicon-based cousins. If you handle them with the precision they deserve, you’ll be rewarded with reliable, high-quality results.

If not, the damage might not show up immediately but rear its head later. Handle with care to reap the full benefits of these devices, including those of the world’s most sensitive 1550-nm noiseless InGaAs APD sensors.

Christian Rookes is VP of marketing at Phlux Technology, a manufacturer of avalanche photodiode (APD) infrared sensors based in Sheffield, UK. He has over 25 years’ experience in technical marketing in semiconductors and optical communications. He holds two patents, including one related to impedance matching for laser diode circuits.

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The post Handle with care: Power and perils of compound semiconductors appeared first on EDN.

Just sharing a bit of a personal epiphany. While browsing through some old schematics at work as reference for a new design, I saw these photocoupler circuits with the NPN transistor outputs used as a high-side switch. I thought to myself "this design can't be right!" and after some research found the below documentation. The base is left floating and some magic from how the LED light affects the phototransistor section causes current to flow from the collector through the base which allows the NPN output to be used for both low-side or high-side configurations. Mind Blown. If anybody knows more about how the magic works, I'd love to read up. How Photocouplers / Optocouplers Are Used submitted by /u/tynkerd [link] [comments]

Found this on AliExpress so I don’t know how good it will be. But I’m learning electronics and electrical engineering so I think this will be a good easy project. \ The kit looks fairly easy as it will have instructions but it will be good practice for me to learn soldering more. Seen lost if people use these mats so I thought I’d get one! \ Very excited for it to arrive so I can try build it. I will post updates ! submitted by /u/Glittering_Ad3249 [link] [comments]

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I got a big old heavy transformer from a long decommissioned mainframe computer. Around 800-1000VA capable primary and a bunch of single and center-tapped secondaries. The strong secondary is a center tapped 88V one and I thought I utilize this somehow for my 2x LJM L20 amplifier modules. Then I recognized I only have 1x fat diode bridge (as 1 package) and a handful of Vishay Hexfred single diodes. But a classic Graetz bridge would give me +/- 44V rails so I needed a trick - and here it is. Reversing a classic bridge's 2 diodes on its left side, it gives me 2 positive rails (referenced to ground) which is perfect then for the 2 modules, voltages also just perfect. This still remains a 2-way rectifier, with a 100Hz pulse cycle (in Europe) and non-magnetizing with respect to the transformer's iron core, retaining great efficiency. Electronics is great !! submitted by /u/pleiad_m45 [link] [comments]

Small project with arduino unosmall project with arduino uno submitted by /u/Repulsive-Rule-3604 [link] [comments]

КПІ ім. Ігоря Сікорського співпрацюватиме з ПУМБ kpi пт, 07/04/2025 - 23:24

Робочі групи з гендерної рівності: напрями діяльності визначено Інформація КП пт, 07/04/2025 - 16:44

Together with UK-based Compound Semiconductor Applications (CSA) Catapult and Quebec-based MiQro Innovation Collaborative Centre (C2MI), the National Research Council of Canada (NRC) has put in place a memorandum of understanding (MoU) to deepen connections and grow a strong and resilient semiconductor supply chain for Canada, the UK, and other G7 countries...

Зустріч з представниками турецької технологічної компанії ASPILSAN Enerji kpi пт, 07/04/2025 - 15:31

Two-phase cooling

Thermal management is an ongoing concern for many designs. The process usually begins with a tactic for dissipating or removing heat from the primary sources (mostly but not exclusively “chips”), then progresses to keeping the circuit-board assembly cool, and finally getting the heat out of the box and “away” to where it becomes someone else’s problem. Passive and active approaches are employed, involving some combination of active or passive convection, conduction (in air or liquid), and radiation principles.

The search for an effective cooling and thermal transfer solution has inspired considerable research. One direct approach uses microchannels embedded within the chip itself. This allows coolant, usually water, to flow through, efficiently absorbing and transferring heat away.

The efficiency of this technique is constrained, however, by the sensible heat of water. (“Sensible heat” refers to the amount of heat needed to increase the temperature of a substance without inducing a phase change, such as from liquid to vapor.) In contrast, the latent heat of phase change of water—the thermal energy absorbed during boiling or evaporation—is around seven times greater than its sensible heat.

Two-phase cooling with water can be achieved by using the latent heat transition, resulting in a significant efficiency enhancement in terms of heat dissipation. Maximizing the efficiency of heat transfer depends on a variety of factors. These include the geometry of the microchannels, the two-phase flow regulation, and the flow resistance; adding to the task, there are challenges in managing the flow of vapor bubbles after heating.

Novel water-cooling system

Now, a team at the Institute of Industrial Science at the University of Tokyo has devised a novel water-cooling system comprising three-dimensional microfluidic channel structures, using a capillary structure and a manifold distribution layer. The researchers designed and fabricated various capillary geometries and studied their properties across a range of conditions to enhance thin-film evaporation.

Although this is not the first project to use microchannels, it presents an alternative physical arrangement that appears to offer superior results.

Not surprisingly, they found that both the geometry of the microchannels through which the coolant flows and the manifold channels that control the distribution of coolant influence the thermal and hydraulic performance of the system. Their design centered on using a microchannel heat sink with micropillars as the capillary structure to enhance thin-film evaporation, thus controlling the chaotic two-phase flow to some extent and mitigating local dry-out issues.

This was done in conjunction with three-dimensional manifold fluidic passages for efficient distribution of coolant into the microchannels, Figure 1.

Figure 1 Microfluidic device combining a microchannel layer and a manifold layer. (A) Schematic diagrams of a microfluidic device. Scale bar: 5 mm. (B) Exploded view of microchannel layer and manifold layer. The heater is located on the backside of the substrate with parallel microchannels. Both the microchannel layer and manifold layer are bonded with each other to constitute the flow path. (C) The coolant flows between the manifolds and microchannels to form an N-shaped flow path. The capillary structures separate the vapor flow from the liquid thin film along the sidewall. The inset schematic shows the ordered two-phase flow under ideal conditions. Scale bar: 50 mm. (D) Cross-sectional schematic view of bonded device showing the heat and fluid flow directions. (E) Clamped device is mechanically tightened using bolts and nuts. (F) Images of clamped device showing the isometric, top, and side views. Scale bar, 1 cm. Source: Institute of Industrial Science at the University of Tokyo

Testing this arrangement requires a complicated electrical, thermal, and fluid arrangement, with clamps to put just the right calibrated pressure on the assembly for a consistent thermal impedance, Figure 2. They also had to allow time for start-up thermal transients to reach steady-state and take other test subtleties into account.

Figure 2 The test setup involved a complicated arrangement of electrical, thermal, mechanical, and fluid inputs and sensors, all linked by a LabVIEW application; top: system diagram; bottom: the actual test bench. Source: Institute of Industrial Science at the University of Tokyo

Their test process included varying key physical dimensions of the micropillars, capillary microchannels, and manifolds to determine optimum performance points.

It’s difficult to characterize performance with a single metric, Figure 3.

Figure 3 Benchmark of experimentally demonstrated critical heat flux and COP of two-phase cooling in microchannel using water. Zone 1 indicates the results in this work achieving efficient cooling by using a mass flow rate of 2.0 g/min with an exit vapor quality of 0.54. The other designs using manifolds marked by solid symbols in zone 2 consume hundreds of times of water with an exit vapor quality of around 0.1. The results of microstructure-enhanced designs are marked by open symbols in zone 3. Zone 4 shows the performance of typical single-phase cooling techniques. Source: Institute of Industrial Science at the University of Tokyo

One such number, the measured ratio of useful cooling output to the required energy input (the dimensionless coefficient of performance, or COP) reached up to 105, representing a meaningful advance over other water-channel cooling techniques that are cited in the references.

Details including thermal modeling, physics analysis, device fabrication, test arrangement, full data, results, and data discussion are in their paper “Chip cooling with manifold-capillary structures enables 105 COP in two-phase systems” published in Cell Reports Physical Science.

As noted earlier, this is not the first attempt to use microchannels to cool chips; it represents another approach to implementing this tactic. Do you think this will be viable outside of a lab environment in the real world of mass-volume production and liquid interconnections? Or will it be limited to a very small subset, if any, of enhanced chip-cooling solutions?

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

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• Micropillar surface yields lower-temperature boiling, better heat shedding

The post Can microchannels, manifolds, and two-phase cooling keep chips happy? appeared first on EDN.

• Rural Rising initiative has reached more than 350,000 individuals across Bangarpet and Mulabagilu Taluks
• New Taluk-Level Community Library launched to enhance educational access

Applied Materials India Private Limited in partnership with United Way Bengaluru (UWBe) celebrated a decade of transformative impact in the Kolar district through their flagship initiative, The Rural Rising. This milestone celebrates a journey of growth, sustainable development, and community empowerment that has reached more than 350,000 individuals across 288 villages in Bangarpet and Mulabagilu taluks.

To commemorate the occasion, a Taluk-level community library was inaugurated, reinforcing the initiative’s commitment to educational access and lifelong learning. Avi Avula, Country President of Applied Materials India and Vice President, Semiconductor Products Group, Asia, along with Rajesh Krishnan, CEO, United Way Bengaluru attended the event.

“This milestone is not just a celebration of what we’ve achieved, but a reaffirmation of what’s possible when business, community, and purpose come together”, said Avi Avula. “The Rural Rising initiative has shown us the power of sustained engagement in driving meaningful change”, he added.

A Model for Sustainable Rural Development

Launched in 2015, The Rural Rising initiative was conceived by United Way Bengaluru and implemented by Applied Materials India to address the unique needs of rural communities through a four-pillar approach: education, environment, health, and livelihood. Key achievements over the past decade include:

• Education:
  • 2,299 students mentored and supported through scholarships and enriched learning environments
  • Launch of a new community library to promote literacy and digital access
• Environment:
  • 7 lakes rejuvenated
  • 434 solar-powered streetlights installed
  • 203 tonnes of CO₂ emissions reduced annually
• Livelihoods:
  • 1,170 women, people with disabilities, and rural youth empowered with income-generating skills
  • 561 farmers supported through soil and water conservation programs
  • 8+ community water ATMs installed, benefiting over 4,000 residents
  • Improved sanitation and hygiene infrastructure across villages

“Collaboration is at the heart of the Rural Rising flagship program. By partnering with Applied Materials India, local authorities, and the community, we have made sure that local perspectives are taken into the development process, from planning to implementation. This way, we are helping them take charge of their own progress and build lasting, self-sustaining change in Kolar, said Rajesh Krishnan, CEO of United Way Bengaluru.”

Scaling the Vision Beyond Kolar

Inspired by the success in Kolar, Applied Materials India and UWBe have expanded The Rural Rising to Coimbatore (Tamil Nadu), and Khed Taluk (Pune, Maharashtra). These new chapters will build on the proven model, focusing on education, sports infrastructure, and ecological sustainability. With continued investment and collaboration with local governments, the initiative is poised to scale its impact and enable long-term, community-driven transformation across rural India.

The post Applied Materials India and United Way Bengaluru Mark 10 Years of Rural Transformation in Kolar appeared first on ELE Times.

This pcb includes: RP2040 Microcontroller – Dual-core Arm Cortex-M0+ @ 133MHz 16MB Flash – Plenty of room for Ducky scripts, firmware, and more USB-C & USB-A Ports – Dual USB Micro SD Card Slot – Store payloads, logs, or configs externally RGB Neopixels – Visual feedback for status, payload execution, etc Compact Custom PCB – Designed with portability and DIY hacking in mind It’s a BadUSB that should act like a keyboard when you plug it in That means it can type lightning-fast and run commands on a computer just like a human would — but in milliseconds. here is the repo https://github.com/souptik-samanta/Hackducky and kicanvas Here Thank you for reading and every input is appreciated submitted by /u/PTSSSINZOFF [link] [comments]

Якщо триматимемося гуртом, подолаємо всі труднощі! kpi пт, 07/04/2025 - 07:29

Aimed at AI/ML applications, Renesas’ RA8P1 MCUs leverage an Arm Ethos-U55 neural processing unit (NPU) delivering 256 GOPS at 500 MHz. The 32-bit devices also integrate dual CPU cores—a 1-GHz Arm Cortex-M85 and a 250-MHz Cortex-M33­—that together achieve over 7300 CoreMark points.

The NPU supports most commonly used neural networks, including DS-CNN, ResNet, Mobilenet, and TinyYolo. Depending on the neural network used, the Ethos-U55 provides up to 35× more inferences per second than the Cortex-M85 processor on its own.

RA8P1 microcontrollers provide up to 2 MB of SRAM and 1 MB of MRAM, which offers faster write speeds and higher endurance than flash memory. System-in-package options include 4 MB or 8 MB of external flash memory for more demanding AI tasks.

Dedicated peripherals and advanced security features support voice and vision AI, as well as real-time analytics. For vision AI, a 16-bit camera engine (CEU) handles image sensors up to 5 megapixels, while a separate two-lane MIPI CSI-2 interface provides a low pin-count connection at up to 720 Mbps per lane. Audio interfaces including I²S and PDM enable microphone input for voice AI. To protect edge AI and IoT systems, the devices integrate cryptographic IP, enforce immutable storage, and monitor for physical tampering.

The RA8P1 MCUs are available now in 224-pin and 289-pin BGA packages.

RA8P1 product page

Renesas Electronics 

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ST’s VIPER11B voltage converter integrates an 800-V avalanche-rugged MOSFET with PWM current-mode control to power smart home and lighting applications up to 8 W. On-chip high-voltage startup circuitry, a senseFET, error amplifier, and frequency-jittered oscillator help minimize external components. The MOSFET requires only minimal snubbing, while the senseFET enables nearly lossless current sensing without external resistors.

As an off-line converter operating from 230 VAC, the VIPER11B consumes less than 10 mW at no load and under 400 mW with a 250-mW load. Under light-load conditions, it operates in pulse frequency modulation (PFM) mode with pulse skipping to enhance efficiency and support energy savings. The controller runs from an internal VDD supply ranging from 4.5 V to 30 V.

Housed in a compact 10-pin SSOP package, the converter conserves space—especially in designs with strict form factors like LED lighting drivers and smart bulbs. It’s also well suited for home appliances, low-power adapters, and smart meters. The device includes output overload and overvoltage protection with automatic restart, along with VCC clamping, thermal shutdown, and soft-start features.

In production now, VIPER11B voltage converters are priced from $0.56 each in lots of 1000 units.

VIPER11B product page

STMicroelectronics

The post Off-line converter trims component count appeared first on EDN.

Designed for automotive use, Murata’s 50-V multilayer ceramic capacitor (MLCC) delivers higher capacitance in a compact 0805-size (2.0×1.25-mm) SMD package. With a rated capacitance value of 10 µF, the GCM21BE71H106KE02 ranks among the smallest in its class.

The capacitor operates on 12-V automotive power lines while conserving PCB space and reducing the overall capacitor count. It delivers approximately 2.1 times the capacitance of Murata’s earlier 4.7-µF/50-V model in the same 0805 footprint. Compared to the previous 10-µF/50-V MLCC in the larger 1206 size (3.2×1.6 mm), it occupies about 53% less board area, offering significant space savings for automotive designs.

The GCM21BE71H106KE02 10-µF/50-V capacitor in the 0805 package is now in production. Use the product page link below to request samples, get a quote, or check availability.

GCM21BE71H106KE02 product page

Murata Manufacturing 

The post MLCC saves board space in vehicle designs appeared first on EDN.