DRV10970EVM: Rotational speed difference depending on direction (FR) in DRV10970EVM driver

Hi Cem Zorlu,

Is this fan motor? Is it seeing lower load in other direction and hence able to spin at higher speed? Can you check current drawn in either direction?

Thanks and Best Regards,

Venkatadri S

Hi Venkatadri Shantaram,

This is not a fan. The phase currents are not the same when the motor rotates in different diractions. The motor operates without load. When we use this motor with another motor driver, it rotates at the same speed in both directions and the phase currents are the same.

Hi Cem Zorlu,

Looks like CMTMOD issue, can you check DAA pin status, CMTMOD and what is preferred for your motor?

Also, is it Trapezoidal or Sinusoidal?

Please test with different CMTMOD and let me know how it works?

Thanks and Best Regards,

Venkatadri S

Hi Venkatadri,

Pins status:

CMTMOD LOW, DAA Floating, BRKMOD HIGH -----> EVM board works best in this pin state. Power consumption 0.8W.

When CMTMOD changes, it does not rotate correctly and consumes too much power. (CMTMOD HIGH >12W, CMTMOD Floating 7W)

Hi Cem,

Thanks for posting to the e2e motor drivers forum. 

Our team expert on this device is out of office for a week, so responses to this debug thread will be delayed until he returns next week.

Please give us some additional time to address your questions/concerns, and feel free to add further information to the thread in the meantime if you believe it will help the debug effort. 

Best Regards, 
Andrew 

Hi Cem,

We need to check if there is any other issue, without load 12W or 8W is too high. Let me check and get back to you.

Meanwhile if you have any more inputs for me, please provide.

Thanks and Best Regards,

Venkatadri S