DRV120: OK to power VIN after other inputs?

EE User 52

Part Number: DRV120

My question is about power sequencing on the DRV120. I'm powering the VIN input on my DRV120 from 24V. The EN input goes to a 3.3V logic level GPIO on a microcontroller. I have the STATUS port connected to an LED & resistor pulled up to 5V (lights when solenoid driven by OUT). Due to the nature of our system, the 3.3V & 5V supplies come up 1st then the 24V supply comes up ~1 minute later. Is there any issue w/ powering the DRV120 in this fashion? Thx for any info.

over 6 years ago

0 Aaron Goodson over 6 years ago

TI__Expert 6330 points

Hi,

I have notified our expert regarding this topic. Please expect a response by 8/29/19.

Thanks,

Aaron

0 Costin Cazana over 6 years ago

TI__Expert 4940 points

Hi,

This is not a supported DRV120 and untested power sequence.

In a clean environment should not be an issue, but any glitches on the power supply may created unexpected results.

Regards,

Costin

0 EE User 52 over 6 years ago in reply to Costin Cazana

Prodigy 60 points

Thx for the reply Costin. This doesn't completely resolve my issue but it helps. We'll power up the DRV120 at the same time as the rest of logic and hopefully that will address our problem. Thx again.

0 Costin Cazana over 5 years ago in reply to EE User 52

TI__Expert 4940 points

Hi,

Actually that's my concern, ramping both Vin and Enable at the same time. That's a potential race condition when device turns on ( Vin voltage)

and Enable voltage. Try to avoid 1.3V<Enable<1.65V when Vin reaches ~5V

Regards,

Costin

0 EE User 52 over 5 years ago in reply to Costin Cazana

Prodigy 60 points

Hi Costin,

Thx for the clarification. My circuit has a 5.1KΩ pulldown to GND on each Enable input. Since the Enable is connected to a uC GPIO (which at start up is a high impedance input), then the Enable should be held low as VIN is brought up. So I'm assuming there isn't a race condition.

Rgds,

Henry

0 Costin Cazana over 5 years ago in reply to EE User 52

TI__Expert 4940 points

Hi Henry,

For this power up sequence I don't see any potential issue.

Regards,

Costin

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DRV120: OK to power VIN after other inputs?