TPS54341: PWRGD signal reading high after power fail

soumya bhat

Part Number: TPS54341

We are using TPS54341 in our application. After power fail, PWRGD signal is going LOW for 10 seconds and after that it is reading HIGH. Where as VIN, EN, FB and SW pins are LOW. Can anybody tell us the reason and how to make this pin low when there is a power fail.

over 8 years ago

0 JohnTucker over 8 years ago

TI__Guru**** 191445 points

If your VIN is low (near 0 V), then the TPS54341 is not turned on and it has no way to control the PWRGD function. If the PWRGD pin is pulled up to an active power rail, that will pull PWRGD high. Can you verify that your input voltage is not present at that time?

0 soumya bhat over 8 years ago in reply to JohnTucker

Prodigy 60 points

Yes input voltage is 0V because we are checking the condition at power fail. I measured VIN it read 0V.

0 JohnTucker over 8 years ago in reply to soumya bhat

TI__Guru**** 191445 points

OK, with VIN = 0 V, the PWRGD signal is not controlled. Any external voltage can pull it up.

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TPS54341: PWRGD signal reading high after power fail