DRV8306: Motor is taking high current

Hi Ancy, 

Thanks for posting to the e2e forum - our team members are currently OOO today for the holidays, but are returning later this week.
Please anticipate a response around then to address your concerns 

Best Regards, 
Andrew 

We are waiting for the response for the last 9 days

Hi Ancy,

I apologize for the delay.

When you are measuring the 4A, what is the voltage that you are getting at that point?

Best,

~Alicia

Alicia Rosenberger said:

When you are measuring the 4A, what is the voltage that you are getting at that point?

I think 24v as he had referenced to 24v and 200mA motor no load current spec.

Brian

Hi Ancy,

ANCY MUHAMMED said:

By increasing the dutycycle to 97% the speed reaches 20K rpm and at no load it is taking almost 4A. What may be the possible reasons for increase in the current at no load.

I think the reason is that at high rpm, the Hall signals timing is not optimized for this motor, causing low efficiency and high loss. 

Solution:

Advance the Hall signals by rotate the Hall devices opposite of the rotor direction slightly until the motor current is at minimum.

The better way is to use a driver with adjustable Hall timing to optimize at high motor speed, or use a MCP to read the Hall signals and adjust the timing, but use a diff driver with 3 or 6 pwm inputs.

Brian