LM5170: nFAULT pin output condition

Hisao Uchikoshi

Part Number: LM5170
Other Parts Discussed in Thread: LM5171,

Hi Experts,

I would like to confirm the condition when nFAULT pin outputs low. For my customer's use-case, since the circuit barker is not required, SYNCOUT pin is pulled low with 10K ohm resister. In this scenario, nFAULT pin output has no meaning meaning never drive low output. Is this understanding correct?

Also, when SYNCOUT pin is left to open, nFAULT can be used to detect the short between source and drain of FET before stating up. Even if other fault conditions like overvoltage, overcurrent and thermal shutdown occur, nFAULT pin does not drive low. Is this understanding correct?

Regards,

Uchikoshi

over 3 years ago

0 Yinsong Cai1 over 3 years ago

TI__Expert 7450 points

Hi Uchikoshi,

Thank you for reaching out.

Yes, as the fault check function is disabled, the nFault pin will remains high even there is short circuit.

Yes, the nFault pin is only internally pulled low to report short circuit failure.

Thanks,

Yinsong

0 Hisao Uchikoshi over 3 years ago in reply to Yinsong Cai1

TI__Genius 14900 points

Hi Yinsong,

Thank you for your confirmation.

Not for now but for future project, will TI have any roadmap devices which can notify failure status to external MCU as many as possible?

Regards,

Uchikoshi

+1 Yinsong Cai1 over 3 years ago in reply to Hisao Uchikoshi

TI__Expert 7450 points

Hi Hisao,

We will have LM5171 as the next gen of LM5170 which integrates I2C that can give different failures status. Please contact through email if you are interested in getting more information.

Thanks,

Yinsong

Power management

Power management forum

LM5170: nFAULT pin output condition