TPS54331: Soft start cap

Robin Yu

Part Number: TPS54331

Hi team,

In datasheet, it shows the soft-start cap could not exceed 27nF, is there any risk if the cap is too big, such as 100nF?

Thanks.

Robin

over 7 years ago

0 Jason Wang (BSR-MV) over 7 years ago

TI__Genius 9550 points

Robin,
Think about test condition: EN Hihg -> pull low-> pull high
if the period "pull low" is short and Css is too big, Css can't be discharged completely. When EN pull high, Css voltage is not 0V which results in inrushing current large.

0 Robin Yu over 7 years ago in reply to Jason Wang (BSR-MV)

TI__Intellectual 2190 points

Hi Jason,
So similar issue may occur when fast switching on-off-on test? Thanks.
Robin

Power management

Power management forum

TPS54331: Soft start cap