DRV8704: UVLO bit

NAOKI AOYAMA

Guru 11215 points

Part Number: DRV8704

Hello,

Our customer use the DRV8704, check the UVLO function.

When the voltage of VM falls below the UVLO threshold, it stops all FET, UVLO bit is set and nFAULT pin is Low.

The customer confirmed that it's operate correctly.

When the voltage of VM rise above UVLO threshold, operation resume and nFAULT pin is High, but UVLO bit is

not clear.

Does it need to write '0' to UVLO bit for clear?

It is mentioned UVLO bit is Read only on the datasheet.

Best Regards,

Naoki Aoyama

over 7 years ago

0 Rick Duncan over 7 years ago

TI__Guru** 114905 points

Hi Aoyama-san,

Yes, a 0 must be written to clear the bit. Rev D of the datasheet states this:

0: Normal operation
1: Undervoltage lockout
Write a ‘0’ to this bit to clear the fault and resume
operation
The UVLO bit cannot be cleared in sleep mode
Operation automatically resumes once VM has
risen

0 NAOKI AOYAMA over 7 years ago in reply to Rick Duncan

Guru 11215 points

Hello Rick-san,

Thank you for your reply.
I'll suggest the customer to follow the table 11.

Could you update the datasheet?
The customer confuse which is the correct description section 7.3.9.4 and 7.5.1.8.

Thanks,
Naoki Aoyama

0 Rick Duncan over 7 years ago in reply to NAOKI AOYAMA

TI__Guru** 114905 points

Hi Aoyama-san,

We will correct this in a future update. Thank you for your comment.

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DRV8704: UVLO bit