DRV8213: Open drain indicator

Hideki Hayashi1

Part Number: DRV8213

Hi team,

/FAULT and /STALL pin are open-drain output, but there is pull-up source inside of IC when I see the block diagram. If i use Vcc=3.3V, is there any issue by pull-ed up to 1.8V externally in order to connect to 1.8V MCU?

Regards,

Hayashi

8 months ago

0 Keerthivasan Kumanan 8 months ago

TI__Expert 8385 points

Hello Hayashi-san,

Is there a reason why VCC itself can't be supplied with 1.8 V.

Best,

Keerthi

0 Hideki Hayashi1 8 months ago in reply to Keerthivasan Kumanan

TI__Expert 6590 points

Hi Keerthi,

There are limited available connector between MCU and DRV8213 as below. Is customer able to operate without issue?

Regards,

Hayashi

0 Keerthivasan Kumanan 8 months ago in reply to Hideki Hayashi1

TI__Expert 8385 points

Hi Hayashi-san,

There is no internal pullup on nFAULT (block diagram mistake) and for the nSTALL has an internal pullup that gets disabled after startup. The setup should be fine as VIH is 1.45 V.

Best,

Keerthi

0 Hideki Hayashi1 8 months ago in reply to Keerthivasan Kumanan

TI__Expert 6590 points

Hi Keerthi,

Keerthivasan Kumanan said:
for the nSTALL has an internal pullup that gets disabled after startup

Could you please explain clearly? Do yo mean there are no valid internal pull-up while Vcc is supplied?

Keerthivasan Kumanan said:
The setup should be fine as VIH is 1.45 V.

I think the spec is for input. Please consider whether it is alright to put two different voltage on the same open-drain output?

Regards,

Hayashi

0 Keerthivasan Kumanan 8 months ago in reply to Hideki Hayashi1

TI__Expert 8385 points

Hello Hayashi-san,

The internal pullup on nSTALL is used internally to see if stall detection is enabled or not on power up (nSTALL to GND to disable). After that initial start up that pullup path gets disabled. The customer application still looks fine to me as it will still register as a logic high.

Best,

Keerthi

0 Hideki Hayashi1 8 months ago in reply to Keerthivasan Kumanan

TI__Expert 6590 points

Hi Keerthi,

I think i can understand. Let me summarize again. After start-up, the internal pull-up resistor to Vcc is disbaled, so open-drain output will not be 3.3V, will be 1.8V from external pull-up source when the motor is not stall. Is it correct?

Regards,

Hayashi

0 Keerthivasan Kumanan 8 months ago in reply to Hideki Hayashi1

TI__Expert 8385 points

Hello Hayashi,

Yes, you are correct.

Best,

Keerthi

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DRV8213: Open drain indicator