TPS2556/57 1kohm resistor in Auto-Retry Functionality application

KIYOSHI NARISAWA1

Expert 1510 points

Other Parts Discussed in Thread: TPS2556, TPS2553, TPS2561, TPS2560, TPS2552

Dear TI

Customer has a question of TPS2556/2557 in Figure20 on datasheet page14.

1kohm resistor is connected to fault pin in series with 100kohm.

But similar devices which TPS2553 and TPS2561 are not 1kohm resister in fi.

What porpuse is 1ohm resistor for?

Thank you for your cooperation.

Best regards

K.Narisawa

over 10 years ago

0 Aleksandras_Kaknevicius over 10 years ago

TI__Genius 15770 points

Hi,

This part falls under the Power Interface group. I will go ahead and move this thread to their forum.

Regards,

Alek Kaknevicius

0 Eric Wright over 10 years ago in reply to Aleksandras_Kaknevicius

TI__Mastermind 42795 points

The 1k resistor is not required at all for the auto-retry circuit for either part family (TPS2552/3, TPS2556/7, TPS2560/1). The 1k resistor can reduce the FAULTx sink current spike (from the EN capacitor) and also add some extra delay from FAULTx falling to EN trip point. But, it is not required for the basic auto-retry function.

0 KIYOSHI NARISAWA1 over 10 years ago in reply to Eric Wright

Expert 1510 points

Hi Aleksandras-san and Eric-sanThank you so much.I understood.Best regards
K.Narisawa

Power management

Power management forum

TPS2556/57 1kohm resistor in Auto-Retry Functionality application