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FBI agent , 12-06-2023, 07:35 AM

Hi Community,
I'm working on an automotive sensor. Here, I'm supposed to build a power line filtering network. What is the first step that i need to do ? I've a PMIC module that switching about 2.1MHz strongly. This switching frequency can lead us to fail CE tests. To figure it out, The first step might be to build power line filter by thinking and estimating. After that, i measure the conducted emission in my own laboratory when i get the PCB. Finally, According the results, I'll be able to build appropriate filter network. Isn't it ? If you have any idea for better time management for it, please suggest me. Thanks in advance.

QDrives , 12-06-2023, 09:14 PM

Any switching frequency can cause you to fail EMC tests. It is not the frequency.
Enough bulk caps and decoupling, shielded inductor, return paths and good layout.
Conducted emissions can be simulated in LTSpice by adding all the parasitics, but radiated emissions...

FBI agent , 12-07-2023, 06:39 AM

you're right, what you recommend me as steps to move on final stage ? Propably, the milestones might be like that :
1-) Determine the frequency components they have maximum power
2-) Take precautions to prevent those components such as place decoupling capacitor/capacitoors that shows minimum impedance for determined frequency component.
3-) Handle the PCB and do experimental test(by oscilloscope etc.). According the results, update power line filter network.
4-) Order new PCB and measure the noise levels for CE aspectation.
5-) you're in the final stage :)))

Robert Feranec , 12-07-2023, 06:42 AM

Did you see my video with Min? Maybe that could help a little bit? https://youtu.be/Lf51sx6sC0I?si=C6gLCN5djK3DU5Oj

FBI agent , 12-07-2023, 06:47 AM

Yes, i watched it but i'm gonna take a look this video again by taking notes. After the video ends, i'll write here if i have still no idea. Thanks Mr. Robert

QDrives , 12-07-2023, 09:28 PM

https://www.youtube.com/watch?v=QEAzcaiBrpY