DRV8426: Internal structure of Vref pin

Yuta Nishie

Genius 4965 points

Part Number: DRV8426

Hi,

Please tell me if there is a pull-down resistor inside the Vref pin.

I looked at the block diagram in the datasheet, but didn't understand.

Best Regards,

Nishie

over 4 years ago

0 Wang5577 over 4 years ago

TI__Guru 56650 points

Nishie,

VREF can be connected to a voltage source which is lower than 3.3V.

Regards,

Wang Li

0 Yuta Nishie over 4 years ago in reply to Wang5577

Genius 4965 points

Hi Wang Li,

Thank you for your reply.

You said it is connected to a voltage lower than 3.3V.

Is it okay to recognize that even if the Vref is open, the voltage will never exceed 3.3V?

Best Regards,

Nishie

0 Wang5577 over 4 years ago in reply to Yuta Nishie

TI__Guru 56650 points

Nishie,

Yes. If the Vref is open, the voltage will be lower than 3.3V. But, in a real application, Vref is for the output current setting and should not be float.

Regards,

Wang Li

+1 Wang5577 over 4 years ago in reply to Wang5577

TI__Guru 56650 points

Nishie,

Another update: Vref pin has a 500kohm pull-down resistor. If VREF is floating, the voltage is zero. I modified my first post.

Regards,

Wang Li

0 Yuta Nishie over 4 years ago in reply to Wang5577

Genius 4965 points

Hi Wang Li,

Thank you fir your support.

I understood Vref pin has a 500kohm pull-down resistor.

Best Regards,

Nishie

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DRV8426: Internal structure of Vref pin