Posts by Nick Alexeev
ESD precautions can save a lot of tedious failure analysis. A very inconvenient thing about ESD is that a failure can be attributed to ESD only by ruling out every other possible cause. ESD failu...
The efficiency of the LDO is a function of the input and output voltages. $$\eta = \frac {P_{out}} {P_{in}} = \frac {I_{out} V_{out}} {I_{in} V_{in}}$$$I_{out} \approx I_{in}$ for a series linear ...
What are the essential safety features of such types of hardware? One option to make such hardware safer is to make it battery powered. What other safety features are generally recommended? ...
[Disclaimer. This is not for an academic class. I'm self-studying.] I’m reading an introductory book on DSP for audio and computer music [Steiglitz 1996, ISBN 0-8053-1684-1 p. 287]. One of the ...
If a data sheet gives the thermal noise (of +3/-3 standard deviations) as 1 uVpp does it mean that out of every thousand samples, 3 will have noise more than ±1 uV at any sample rate? 1000 sps wi...
[I used to work at Microchip.] Is it [node size] at all important [for power management ICs] ? For power conversion ICs cutting edge MOSFETs on the scale of 5nm aren't important, because powe...
If it is important, how crucial is it that the polygon completely overlaps the ground plane beneath it? A power polygon can hang off the side a of a power plane. Complete overlap isn't crucia...
A MOSFET has its gate, source and drain on the top side [1]. These structures are sitting on top of the substrate, which is also called body or bulk. The source and drain are n-doped, while the...
synopsis Achievable by using a rail-to-rail op-amp. A small bias on the non-inverting input improves the transient response of the op-amp. That’s the second circuit in the O.P. I use such top...
I've got a is self-powered USB device, which means that I have to do VBUS detection. The device is built around STM32G474. Unlike some other STM32s, the STM32G4 don't have a dedicated pin for VBUS...
I want to create a schematic symbol and reuse it for multiple ICs which have identical pinouts. For example, OpaMPS, or the venerable SN74LS00, SN74HC00, SN74HCT00. How can I do this in an Altium...
[I’m asking this question out of curiosity. I understand that this aspect of the CAN bus specification is what it is, and can not change.] The ACK bit in any CAN data frame is dominant. Each rece...
I'd rather use the AD4111 as a high-side current sensor, instead of creating an "inverter" which would generate an equal and opposite current. Each current input of the AD4111 (IINx+ and IINx-) is...
If you put the Fat load-dump TVS downstream of the reverse-polarity protection MOSFET [1], then the load dump current would have to flow through the MOSFET. The MOSFET would have to be rated for t...
[In addition to what Olin wrote earlier.] I looked-up one of the references from the textbook, and I may have found the answer which the author had in mind. This entire spectrum must not be pas...
The electrolytic capacitor acts as a snubber in parallel with the ceramic capacitors. If one were to design an RC snubber to dampen the LC circuit, it would have a large capacitance (compared to t...
A few months ago, I too was looking for answers on how to connect the USB shield with ESD in mind. I always connect the shield through a resistor to ground and a capacitor to ground (100kΩ and 0.0...
Furthermore, an amplifier symbol called "gm" is labeled as transconductor. What does it do? Transconductors are voltage-controlled current sources, but what are they doing here? The diagram lo...
In this case the antenna connector is the standard horrible little U.FL, which is connected with coaxial to a bigger one grounded to chassis. The main ESD risk is when someone is connecting or re...
What you are proposing may be okay (depending on other specifics of the design), but your proposed 4-layer PCB stack-up looks like a compromise. Clock is a high speed signal, and so is SPI dependi...
Another solution which uses an ADC to read the three-state pin on the battery charger IC. The original question mentions GPIO, and doesn’t mention ADC. Maybe this will be useful for some other de...
Is there a mathematical process resembling the terms "digital"/"discrete" and "analog"/"continuous"? Rounding (down, or up, or to the nearest integer) is he mathematical process which discreti...
I've found a solution, and tested it. What @Olin wrote earlier holds. This is to post my code for STM32. Does the VBUS detection have to be done in an interrupt? I've asked the ST's technic...
The 1st page of a datasheet is written by marketing. It can still give you an idea of what the chip is about, but it often contains the performance data under the best conditions. The conditions ...
[In addition to the answers which have already been posted.] A current sensing circuit like this lends itself to another scheme for ESD protection, which uses only one TVS. Only the line in which...
