TPS25830A-Q1: FAULT behaviour at overcurrent condition

Piotr F.

Part Number: TPS25830A-Q1

Tool/software:

TI Team,

My customer use TPS25820A-Q1 in average current limit mode.

They understand from datasheet that FAULT pin at overcurrent conditions will assert only after 128 Buck DC/DC switching cycles, having LS current limit to be at 4.6A ~ 6.2A (tripping) level.

This means:

only hard shorts are indicated by FAULT (datasheet mentions this). Weak overcurrent condition will not be indicated by FAULT pin.
If buck switch at 2MHz, then on hard short, FAULT will assert after 128 Buck DC/DC switching cycles --> it will be 64us delayed (is my math correct? :) ) .

Please confirm my understanding.

over 1 year ago

0 Seong Kim over 1 year ago

TI__Mastermind 46361 points

Hello Piotr,

I will look into this and get back to you.

BR,

Seong

0 Seong Kim over 1 year ago in reply to Seong Kim

TI__Mastermind 46361 points

Hello Piotr,

Your interpretations are correct.

An overcurrent condition will not trigger the FAULT pin. However, a hard short will trigger it.

If the switching frequency is 2MHz, or 2M cycles per second, 128 cycles translates to 64us. I would like to bench test this to confirm. I will provide an update soon.

BR,

Seong