DRV8311: Current sensing closed-loop commutation

Hey Mason,

Could you elaborate a bit more about what you are trying to achieve with the CSA? Like are you trying to have the driver shut down upon reaching a certain current or adjust pwm based on current. 

These are some of the ways CSA output is utilized but really depends on your objective.

Best,
Akshay

Hi Akshay thank you for the reply!

Yes we are wanting to adjust the PWM state register for DC commutation using the CSA output as briefly touched on in the datasheet.

Hey Mason,

Thanks for the background.

May I know what microcontroller your are planning to use with this driver? Usually the microcontroller teams have example software written for drivers that you might be able to reuse or modify for your specific application.

Best,

Akshay

Hi Akshay, we are using a nRF52832 with this driver. 

Thanks

Follow-up question, we were currently planning on only using the 3 current sensing outputs from the DRV8311P to determine our motor position and commutation steps. The more we research this the more we are seeing voltage sensing of the windings instead of current to achieve closed loop control. Is it possible to only use winding current?

Hey Mason,

I am not sure if that microcontroller team provides software solutions. We have our C2000 team's instaspin FOC solution that could be used as a guide.

I am not sure if its possible to do positions sensing with just CSA and usually as you mentioned VSense is used to detect back emf for this purpose.

Best,

Akshay