Feed aggregator

submitted by /u/Fun-Bluejay9161
[link] [comments]

JLCPCB is great for prototyping. But I'm writing this to warn anyone considering using JLCPCB's assembly service for projects involving digital MEMS microphones. I've tried 6 times over the last two years. It has cost me countless hours, endless frustration, and over $2000. Since I do this work for a non-profit organization protecting elephants, the setbacks hurt even more. The PCB is for a wildlife audio recorder – basically a digital MEMS microphone connected to an ESP32. Nothing particularly complex. EDIT: The MEMS mic we use is the ICS-43434 Here’s the timeline of what happened: Order 1 (Apr 2023): For prototyping, I ordered 2 assembled PCBs. One MEMS microphone arrived broken. Neither JLCPCB nor I knew why initially. I spent hours troubleshooting. I specifically asked their support if they followed the correct reflow temperature profiles and if they performed board cleaning (which can destroy these mics). They replied that temperature curves looked good and claimed no board cleaning was done. Order 2 (Aug 2023): Thinking the first failure was a one-off, I ordered 10 PCBs. To my disappointment, 8 out of 10 arrived with broken mics that only recorded noise. Adding an external mic to the same PCB worked fine, confirming the onboard mics were the issue. This time, I removed the cap from the MEMS component and could see the ruptured membrane (See picture). Some also showed bad solder joints. A friend suspected the mic was too close to the panelization rails, causing stress when the rails were broken off. So, for the next design, I moved the mic further away and added a gap to the rail area. Order 3 (Dec 2023): Confident the rail spacing was the fix, I ordered 50pcs. All 50 arrived broken. Again, I opened the MEMS packages with a hot air gun and saw the membranes were shattered. After endless emails, JLCPCB initially offered a tiny coupon of 20USD, which was insulting given the scale of the failure. Eventually, after significant back-and-forth, we settled on $120. I asked how to prevent this, and support told me to add a specific note to my next order asking for extra care. Order 4 (Feb 2024): Following their advice, I ordered again, adding the requested note. Nothing changed – all boards arrived broken. Finally, JLCPCB started investigating properly. They used some of my parts from stock to test their process. And YES, they found the issue: their board cleaning process destroyed the microphones. Specifically, dry ice cleaning after manual soldering was the culprit. Apparently, they do perform cleaning sometimes (especially with through-hole parts), even if you explicitly told them not to. Order 5 (Nov 2024): Armed with JLCPCB's own findings, I explicitly added a remark for my next order of 100 boards ($1500): NO dry ice cleaning without protection. I was reassured by support that the special request would be followed. When the boards arrived... All 100 were broken again... due to dry ice cleaning. JLCPCB admitted their operator failed to follow the instruction. I received a $200 coupon after a long negotiation. Order 6 (Mar 2025): I had almost given up but placed another small prototype order (5 boards) and decided to give the mics one last chance. I wrote the note again: "NO DRY ICE CLEANING or it will destroy the MEMS". I also confirmed with support that the note was in the system and would be followed. When they arrived... No surprise: all membranes broken again, due to the dry ice cleaning process. After this final failure, I told them I was done with JLCPCB and would have to share my experience. Only then did they offer to refund this last order completely, which i refused. That's not how it should work. Based on my documented experience, JLCPCB seems incapable of reliably assembling boards with MEMS microphones or consistently following critical process instructions. If your project uses MEMS mics, I strongly advise you to consider alternatives or proceed with extreme caution. Hope this saves someone else the time, money, and frustration I went through. I have to say that the support contact I had (Emma) was always friendly and tried to be supportive. However, it felt like crucial technical details sometimes got lost in translation when relaying information between me and the engineers. submitted by /u/EDsteve [link] [comments]

I reverse-engineered a no-neutral smart switch from Sonoff. It's like 70% ready, not all values for passive, no MCU board, no PCBs. If someone is interested in collaboration, let me know. submitted by /u/Dear_Cartographer_10 [link] [comments]

I finally got rid of all those cards I had in my nightstand for years😩 submitted by /u/White_Septendecim [link] [comments]

It finally made it work submitted by /u/OtisCanHelpYou [link] [comments]

submitted by /u/toybuilder
[link] [comments]

submitted by /u/AutoModerator
[link] [comments]

I had previously done it on two breadboards, because I had to find space for the push-up buttons, but yesterday I received this type of buttons😄 submitted by /u/White_Septendecim [link] [comments]

Hi submitted by /u/Careful-Rich9823 [link] [comments]

The curators of gallium nitride (GaN) foundry BelGaN of Oudenaarde, East Flanders (Belgium’s last industrial chip manufacturer) – which filed for bankruptcy in July 2024, leaving more than 440 staff unemployed – have reached an agreement for a European investor to acquire the premises for €20.35m (including an advance payment of €2m that has been paid). The facility includes two large cleanrooms, but excludes manufacturing equipment, which was auctioned online between late November and mid-March in about 1800 lots (including wafer processing machines, mainframe computers and other specialized equipment), raising over €23m...

The phasing method

In radio communications, one way to generate single sideband (SSB) signals is to make a double sideband signal by feeding a carrier and a modulation signal into a balanced modulator to create a double sideband (DSB) signal and then filter out one of the two resulting sidebands.

If you filter out the lower sideband, you’re left with the upper sideband and if you filter out the upper sideband, you’re left with the lower sideband. However, another way to generate SSB without that filtering has been called “the phasing method.”

Let’s look at that in the following sketch in Figure 1.

Figure 1 Phasing method of generating an SSB signal where the outputs of Fc and Fm are 90° apart with respect to each other

The outputs of the carrier (Fc) quadrature phase shifter and the modulating signal (Fm) quadrature phase shifter need only be 90° apart with respect to each other. The phase relationships to their respective inputs are irrelevant.

Four cases of SSB generation

In the following equations, those two unimportant phase shifts are called “phi” and “chi” for no particular reason other than their pronunciations happen to rhyme. Mathematically, we examine four cases of SSB generation.

Case 1, where “Fc at 90°” and “Fm at 90°” are both +90°, or in the same directions (Figure 2). Case 2, where “Fc at 90°” and “Fm at 90°” are both -90°, or in the same directions (Figure 3).

Figure 2 Mathematically solving for upper and lower side bands where “Fc at 90°” and “Fm at 90°” are both +90°, or in the same directions.

Figure 3 Mathematically solving for upper and lower side bands where “Fc at 90°” and “Fm at 90°” are both -90°, or in the same directions.

Case 3, where “Fc at 90°” is -90°and “Fm at 90°” is +90°, or in the opposite directions (Figure 4). Case 4, where “Fc at 90°” is +90°and “Fm at 90°” is -90°, or in the opposite directions (Figure 5).

Figure 4 Mathematically solving for upper and lower side bands where “Fc at 90°” is -90°and “Fm at 90°” is +90°, or in the opposite directions

Figure 5 Mathematically solving for upper and lower side bands where “Fc at 90°” is +90°and “Fm at 90°” is -90°, or in the opposite directions.

The quadrature phase shifter for the carrier signal only needs to operate at one frequency, which is that of the carrier itself and which we have called “Fc”. The quadrature phase shifter for the modulating signal however has to operate over a range of frequencies. That device has to develop 90° phase shifts for all the frequency components of that modulating signal and therein lies a challenge.

90° phase shifts for all frequency components

There is a mathematical operator called the Hilbert transform which is described here. There, we find an illustration of the Hilbert transformation of a square wave. From that page, we present the sketch in Figure 6.

Figure 6 A square wave and its Hilbert transform, bringing about a 90° phase shift of each frequency component of the input signal in its own time base.

The underlying mathematics of the Hilbert transform is described in terms of a convolution integral but in another sense, you can look at the result as bringing about a 90° phase shift of each frequency component of the input signal in its own time base, in the above case, of a square wave. This phase shift property is the very thing we want for our modulating signal in SSB generation.

In the case of Figure 7, I took each frequency component of a square wave—by which I mean the fundamental frequency plus a large number of properly scaled odd harmonics—and phase shifted each of them by 90° in their respective time frames. I then added up those phase-shifted terms.

Figure 7 A square wave and the result of 90° phase shifts of each harmonic component in that square wave.

Please compare Figure 6 to the result in Figure 5. They look very much the same. The finite number of 90° phase shift and summing steps very nicely approximate the Hilbert transform. 

The ideal case for SSB generation can be expressed as starting with a carrier signal, you create a second carrier signal at the same frequency as the first, but phase shifted by 90°. Putting this another way, the first carrier signal and the second carrier signal are in quadrature with respect to one another.

You then take your modulating signal and generate its Hilbert transform. You now have two modulating signals in which each frequency component of the one is in quadrature with the corresponding frequency component of the other.

Using two balanced modulators, you apply one carrier and one modulating signal to one balanced modulator and apply the other carrier and the other modulating signal to the other balanced modulator. The outputs of the two balanced modulators are then either added to each other or subtracted from each other. Based on the four mathematical examples above, you end up with either an upper sideband SSB signal or a lower sideband SSB signal.

This offers high performance and thus the costly filters described in the first paragraph above are not needed.

Practically applying a Hilbert transform

As a practical matter however, instead of actually making a true Hilbert transformer (I have no idea how or even if that could be done.), we can make a variety of different circuits which will give us the 90° phase shifts we need for our modulating signals over some range of operating frequencies with each frequency component 90° shifted in its own time frame.

One of the earliest purchasable devices for doing this over the range of speech frequencies was a resistor-capacitor network called the 2Q4 which was made by a company called Barker and Williamson. The 2Q4 came in a metal can with a vacuum-tube-like octal base. Its dimensions were very close to that of a 6J5 vacuum tube, but the can of the 2Q4 was painted grey instead of black. (Yes, I know that I’m getting old.)

Another approach to obtaining the needed 90° phase relationships of the modulating signals is by using cascaded sets of all-pass filters. That technique is described in “All-pass filter phase shifters.”

One thing to note is that the Hilbert transformation itself and our approximation of it can lead to some really spiky signals. The spikiness we see for the square wave arises for speech waveforms too. This fact has an important practical implication.

SSB transmitters tend to have high peak output powers versus their average output power levels. This is why in amateur radio, while there is an FCC-imposed operating power limit of 1000 watts, the limit for SSB transmission is 2000 watts peak power.

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

Related Content

• All-pass filter phase shifters
• Spectral analysis and modulation, part 5: Phase shift keying
• Single-sideband demodulator covers the HF band
• SSB modulator covers HF band
• Impact of phase noise in signal generators
• Choosing a waveform generator: The devil is in the details
• Modulation basics, part 1: Amplitude and frequency modulation

The post Single sideband generation appeared first on EDN.

I've only asked from the internet, lately I realized I must also share. This will be the first piece of information I share, that I would've found valuable if I'd came upon. I was making an LED stroboscope, to make it work, it felt right to overdrive an LED since the on time would be very very short(under 1ms) and a bigger LED would just be a waste. So, I needed information on what would happen if an LED was driven way above the rated forward voltage. Datasheets provide a graph up to 42V for 36V leds, but nothing beyond. There are some written information here and there on the internet that the LEDs are basically thermally limited, but no experiment results. So I improvised an experimental setup and got the data myself. Experimental setup is a modified XL6009 dc-dc step up supply that is adjustable up to 62 Volts, a 1000uf 100V electrolytic capacitor for high voltage storage, a simple optocoupler driven mosfet module available on maker stores, a series shunt resistor of value 0.1 ohms, a digital oscilloscope and a 36V COB LED array SDW01F1C DB3E-V0 made by Seoul. Also a current limiting resistor right after the XL6009 to prevent it from overloading during pulses, as the capacitor is the main LED power supply. A stm32f103 bluepill board triggers the optocoupler-mosfet switch once a second, for 500us. Mosfet switches the bare high DC voltage on the capacitor to the LED. XL6009 output voltage is adjusted in 1 volt steps and resulting voltage drop on the shunt resistor during the LED on time is measured through the oscilloscope. This experimental setup is limited by the XL6009 ic which normally has its output pin voltage listed as 60V in absolute maximum ratings, this setup goes 2 volts above that. I didn't wanna try more. I want to take it further with a higher votlage DC power supply. Findings: As you can see from the graph, the I-V relation is pretty linear, with a slight curve visible. with almost double the voltage, current increases tenfold. Forward current at a certain forward voltage is temperature dependent, I've observed it during the experiment but did not record. The LED only heats up almost as if the average power it's being driven with that average power continuously. Of course, the LED light efficiency drops as the forward current increases, but not by orders. I got the LED pretty hot with extended pulses(60ms at 50V), and the LED was not measurably damaged. It really seems the LED drive current is indeed limited by the junction temperature, and drive conditions way above maximum ratings don't just magically burn things without heating them up first. I reckon you can extrapolate other LEDs I-V graphs upto double the rated forward voltage and be safe, provided that you don't exceed rated power in average. I've also tested a 5mm THT white LED with the same setup and it behaved pretty much in a similiar way. I hope you find it useful. submitted by /u/klazera [link] [comments]

I’ve been getting a new email like this from my preferred PCB vendor almost daily. submitted by /u/fritoburritobandito [link] [comments]

All my capacitors have linked in to a ball. Guessing all the vibrations from shipping did this. submitted by /u/Whyjustwhydothat [link] [comments]

submitted by /u/Riverspoke [link] [comments]

Serial EEPROMs from ST contain a unique 128-bit read-only ID for product recognition and tracking without requiring an extra component. Preprogrammed and permanently locked at the factory, the unique ID (UID) enables basic product identification and clone detection as an alternative to an entry-level secure element.

Initially available in 64-kbit and 128-kbit versions, the M24xxx-U series spans storage densities from 32 kbits to 2 Mbits. Each device retains its UID throughout the end-product lifecycle—from sourcing and manufacturing to deployment, maintenance, and disposal. The UID ensures seamless traceability, aiding reliability analysis and simplifying equipment repair.

These CMOS EEPROMs endure 4 million write cycles and retain data for 200 years. They operate from 1.7 V to 5.5 V and support 100-kHz, 400-kHz, and 1-MHz I2C bus speeds. The devices offer random and sequential read access, along with a write-protect feature for the entire memory array.

The 64-kbit M24C64-UFMN6TP is available now, priced from $0.13, while the 128-kbit M24128-UFMN6TP starts at $0.15 for orders of 10,000 units. Additional densities will be released during the second quarter of 2025.

STMicroelectronics

Find more datasheets on products like this one at Datasheets.com, searchable by category, part #, description, manufacturer, and more.

The post EEPROMs with unique ID improve traceability appeared first on EDN.

Diodes’ AH4930Q sensor detects magnetic fields along the X, Y, and Z axes for contactless rotary motion and proximity sensing. As the company’s first automotive-compliant 3D linear Hall effect sensor, the AH4930Q is well-suited for rotary and push selectors in infotainment systems, stalk gear shifters, door handles and locks, and power seat adjusters.

Qualified to AEC-Q100 Grade 1, the AH4930Q operates over a temperature range of -40°C to +125°C and integrates a 12-bit temperature sensor for accurate on-chip compensation. It also features a 12-bit ADC, delivering high resolution in each measurement direction, down to 1 Gauss per bit (0.1 mT) for precise positional accuracy. An I2C interface supports data reading and runtime programming with host systems up to 1 Mbps, enabling real-time adjustments.

The sensor features three operating modes and a power-down mode with a consumption of just 9 nA. Its modes balance power and data acquisition, ranging from a low-power mode at 13 µA (10 Hz) to a fast-sampling mode at 3.8 mA (3.3 kHz) for continuous measurement. Operating with supply voltages from 2.8 V to 5.5 V, the AH4930Q offers a 10-µs wake-up time, 4-µs response time, and wide bandwidth for fast data acquisition in demanding applications.

Supplied in a 6-pin SOT26 package, the AH4930Q costs $0.50 each in lots of 1000 units.

AH4930Q product page

Diodes

Find more datasheets on products like this one at Datasheets.com, searchable by category, part #, description, manufacturer, and more.

The post 3D Hall sensor meets automotive requirements appeared first on EDN.

Keysight AI (KAI) Data Center Builder emulates AI workloads without requiring large GPU clusters, enabling evaluation of how new algorithms, components, and protocols affect AI training. The software suite integrates large language model (LLM) and other AI model workloads into the design and validation of AI infrastructure components, including networks, hosts, and accelerators.

KAI Data Center Builder simulates real-world AI training network patterns to speed experimentation, reduce the learning curve, and identify performance degradation causes that real jobs may not reveal. Keysight customers can access LLM workloads like GPT and Llama, along with popular model partitioning schemas, such as Data Parallel (DP), Fully Sharded Data Parallel (FSDP), and 3D parallelism.

The KAI Data Center Builder workload emulation application allows AI operators to:

• Experiment with parallelism parameters, including partition sizes and distribution across AI infrastructure (scheduling)
• Assess the impact of communications within and between partitions on overall job completion time (JCT)
• Identify low-performing collective operations and pinpoint bottlenecks
• Analyze network utilization, tail latency, and congestion to understand their effect on JCT

For more information on the KAI Data Center Builder, or to request a demo or price quote, click the product page link below.

KAI Data Center Builder product page

Keysight Technologies 

Find more datasheets on products like this one at Datasheets.com, searchable by category, part #, description, manufacturer, and more.

The post Software optimizes AI infrastructure performance appeared first on EDN.

Leveraging Menlo’s Ideal Switch technology, the MM5230 RF switch minimizes insertion loss and provides high power handling in a chip-scale package. The device is a SP4T switch that operates from DC to 18 GHz, which extends to 26 GHz in SPST Super-Port mode. Designed for high-power applications, it supports up to 25 W continuous and 150 W pulsed power.

The MM5230 is well-suited for defense and aerospace, medical equipment, test and measurement, and wireless infrastructure applications. With an on-state insertion loss of just 0.3 dB at 6 GHz, it minimizes signal degradation, ensuring high performance in sensitive systems, low-loss switch matrices, switched filter banks, and tunable filters. Additionally, the MM5230 provides high linearity with a typical IIP3 of 95 dBm, preserving signal integrity for smooth communication or data transfer.

The switch’s 2.5×2.5-mm chip-scale package eases integration into a wide range of systems and conserves valuable board space. Additionally, the Ideal Switch fabrication process enhances reliability and endurance. 

The MM5230 RF switch is available for purchase through Menlo Microsystems’ distributor network.

MM5230 product page 

Menlo Microsystems 

Find more datasheets on products like this one at Datasheets.com, searchable by category, part #, description, manufacturer, and more.

The post High-power switch operates up to 26 GHz appeared first on EDN.