New Data sheet for DRV8824

John Saunders1

Other Parts Discussed in Thread: DRV8824

The revised data sheet (8/2013), for the DRV8824 specifies a 1M resistor across the capacitor that connects VCP (pin 3) to VM. Why was this added? and what are the risks without it?

over 12 years ago

0 Nicholas Oborny over 12 years ago

TI__Mastermind 21320 points

Hi John,

See note below.

VCP capacitor remains charged for a time after power is removed. This causes high-side FETs to remain on and short across motor windings which makes detent torque high.

Solution is to add bleed resistor (1Mohm) across VCP capacitor.

0 Toshio Ushikubo over 9 years ago in reply to Nicholas Oborny

Mastermind 9620 points

Hello Nick-san,

Please answer following question from customer.

Please let me known the trigger of adding 1M ohm resistor.
I think if both upper FET is ON when VM is OFF, it is slow decay(brake) mode and there isn’t big issue.
Was there any trouble without 1M ohm?

Best Regards.

0 Nicholas Oborny over 9 years ago in reply to Toshio Ushikubo

TI__Mastermind 21320 points

Hi Ushikubo-san,

Correct, motor is in brake mode for a period after power down. This was undesirable for some customers. No other issue without.

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New Data sheet for DRV8824