TPS544B20: TPS544B20 EMI issue

user1932012

Part Number: TPS544B20

HI :

We tested TPS544B20 EMI.FCC Part 15 Class B Electiric Field stength QP-3M, There are too many test values. Attachment is SCH and test data. Please help us see which parameters we can modify and how to pass FCC. Thank you.PMbus.pdf

over 4 years ago

0 JohnTucker over 4 years ago

TI__Guru**** 191445 points

Mark,

I do not see anything obvious. You should look at the switching node waveform to see if there is any ringing that corresponds to the worst frequencies. You are not failing a few individual frequencies, but rather broad ranges. Can we see your PCB layout?

0 JohnTucker over 4 years ago in reply to JohnTucker

TI__Guru**** 191445 points

Mark,

Can you tell me about your test environment? Are you testing in a certified lab? In an EMI shielded chamber? What is your noise floor like? Can we see low frequency down to 100 kHz?

0 user1932012 over 4 years ago in reply to JohnTucker

Intellectual 750 points

We only test the radiation and transmit it to no test. The power supply is 12V lead-acid battery, so we just need to look at 30m ≤ 1GHz. Thank you

0 JohnTucker over 4 years ago in reply to user1932012

TI__Guru**** 191445 points

Mark,

In order to troubleshoot your issue, we need to see a plot of the noise floor in your test environment as well as a sweep that shows the fundamental operating frequencies in the range above 100 kHz. Also we need to check your pcb layout.

0 JohnTucker over 4 years ago in reply to JohnTucker

TI__Guru**** 191445 points

Mark,

I will close this thread for now. You may re-open it at any time.

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TPS544B20: TPS544B20 EMI issue