DRV8313: Comparator COMPN pin low issue

Frank Wu95

Part Number: DRV8313

We have voltage divider connect to this pin, 10K to GND and 3K to V3P3, and 10K to /COMPO and /RESET. COMPP is connected to a thermistor for over temperature control. We have this circuit working fine for 30 boards, but 3 failed due to COMPN is 0.2V after they working for a while, we cut the trace from the divider to PIN22 (COMPN), then the voltage divider works normally. Then it must be the problem of the chip, what could be wrong there, can we get help from the factory to investigate that?

Thanks,

Frank

over 5 years ago

0 Adam Sidelsky over 5 years ago

TI__Guru 65450 points

Frank,

Thanks for posting on the MD forum!

Is it possible to compare the resistance to GND of the COMPP and COMPN pins on one "good" and one "bad" unit?

Please provide a schematic or block diagram of the circuit.

Regards,

-Adam

0 Frank Wu95 over 5 years ago in reply to Adam Sidelsky

Intellectual 390 points

Hi Adam,

The resistance of the good and bad board is listed below,

good bad

COMPP 8.5K 8.5K

COMPN 8K 80ohm

The schematic is attached.

Frank

0 Adam Sidelsky over 5 years ago in reply to Frank Wu95

TI__Guru 65450 points

Frank,

Sorry for the delay here.

It seems like the COMPN pin has been internally damaged.

Have you seen any voltage transients or violations of the ABS max limits on the COMP pins? Could you show us if the COMPP or COMPN pins are connected to any other nodes on your board?

Regards,

-Adam

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DRV8313: Comparator COMPN pin low issue