DRV10970: Direction Reversal Operation in Trapezoidal mode of Commutation

Avish Gupta

Part Number: DRV10970

I am using DRV10970 for precision speed control of a three phase BLDC motor (FaullHauber 2610B). According to my understanding of the datasheet, when you switch/toggle the FR pin state, the motor first brakes and then reverses. However, in "8.4.1.1 Trapezoidal Control Mode", it is stated that "In the trapezoidal control mode, the DRV10970 device drives standard six step commutation sequence based on the Hall input states and FR (direction) pin value." along with the truth table. [Ref : SLVSCU7A, Pg 17, 8.4.1.1]

Is the trapezoidal mode an exception for the FR operation, where changing the FR state directly changes the commutation sequence irrespective of the BRKMOD state.

Thanks and Regards,

Avish Gupta

over 6 years ago

0 Sanmesh Udhayakumar over 6 years ago

TI__Expert 6065 points

Let me verify in lab whether brake actually happens. I'll get back to you on tueday.

0 Sanmesh Udhayakumar over 6 years ago in reply to Sanmesh Udhayakumar

TI__Expert 6065 points

Even in trapezoidal mode, when changing FR pin, regardless of the times you toggle FR pin, the device always enters brkmod, waits until motor stops, waits Cretry time, then starts the motor according to FR pin direction.

0 Avish Gupta over 6 years ago in reply to Sanmesh Udhayakumar

Intellectual 470 points

Thanks

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DRV10970: Direction Reversal Operation in Trapezoidal mode of Commutation