PMP22650: Selected capacitor

Pablo Ballonga

Prodigy 20 points

Part Number: PMP22650

Tool/software:

Hello,

I have a doubt about the selection of the bus electrolytic capacitors.

From the BOM, the capacitors selected are the ALA7DA471DE500 from Kemet. 470uF, 500V and 2.5A@100Hz ripple current.

3 caps in parallel therefore 7.5 A, I’ve estimate and simulate the current ripple across the line cycle, and I have obtained a rms current of 17A.

How it is possible that this cap can handle all the current?

Thanks in advance.

over 2 years ago

0 Darwin Fernandez over 2 years ago

TI__Mastermind 41800 points

Hi Pablo, we are currently looking into this and a response will be posted when available as the original designer for this reference design is currently out of office and will be back the second week of July. It would be good to verify the current ripple with him when he gets back. Thanks!

+1 Brent McDonald over 2 years ago

TI__Intellectual 1805 points

I believe the RMS current is closer to about 12.4 A total. I cannot locate my analysis files, however, you also need to include the impact of the local ceramic capacitors as well.

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PMP22650: Selected capacitor