DRV8703-Q1: purpose of nWDFAULT and nFAULT pins

Viktorija Cecil

Mastermind 18491 points

Part Number: DRV8703-Q1

What is the purpose of nWDFAULT and nFAULT pins? Just to alert the micro of the status?

Are these OK to leave open and unused? I could not find any text in the datasheet regarding this.

Any issue with periodically (on a 1ms loop) checking the status registers for faults?

Thanks

Viktorija

over 5 years ago

0 Madison Eaker over 5 years ago

TI__Prodigy 460 points

Hi Viktorija,

The nFAULT pin is used to detect faults (i.e. VM undervoltage, logic undervoltage, over current, gate driver fault, over temperature).The nWDFLT pin is a MCU watchdog that ensures the external MCU communicating with DRV8703-Q1 is active and known.

The nFAULT pin and nWDFLT pin should be pulled up to 5V or 3.3V supply. We recommend using a 10k or greater pullup resistor.

There is no issue with periodically checking the status registers for faults.

Thanks,

Madison Eaker

Motor Drivers

0 Viktorija Cecil over 5 years ago in reply to Madison Eaker

TI__Mastermind 18491 points

It is OK to disconnect pins nFAULT and nWDFLT from the MCU but still required to pull up the pins to 5V?

0 Madison Eaker over 5 years ago in reply to Viktorija Cecil

TI__Prodigy 460 points

Hi Viktorija,

The nFAULT and nWDFLT pins should be pulled up to 5V or 3.3V because they are open drain outputs. It is okay to disconnect the nFAULT and nWDFLT from the MCU.

Thanks,

Madison Eaker

Motor Drivers

Motor drivers

Motor drivers forum

DRV8703-Q1: purpose of nWDFAULT and nFAULT pins