DRV8701 current chopping

Gino Magarotto

Other Parts Discussed in Thread: DRV8701, DRV8701EVM

Hello,

I recently developed a brushed DC servo drive using the DRV8701 IC, and I was wondering if it is a good idea to feed the VREF pin with a low pass filtered PWM signal from my microntroller, to be able to adjust the motor's maximum current by software, and gain the ability to perform torque control.

over 8 years ago

0 Rick Duncan over 8 years ago

TI__Guru** 114905 points

Hi Gino,

Adding additional capability is good idea, especially when performing initial evaluation.

I would suggest that you include the ability to remove this feature and switch to a fixed VREF as a cost reduction option.

0 Nicholas Oborny over 8 years ago

TI__Mastermind 21305 points

Hi Gino,

This is certainly feasible. We implemented it on the DRV8701EVM if you want an example. You should of course not expect this to be as accurate as a DAC or fixed voltage reference.

0 Gino Magarotto over 8 years ago in reply to Nicholas Oborny

Prodigy 40 points

Thank you, Rick and Nicholas! I'll give it a try and see how it goes.

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

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DRV8701 current chopping