Allegro A89301 BLDC driver- speed response in closed loop

The dynamic response of this device in closed loop speed control is slow. The Application Note mentions in page 21 that “when closed loop speed control is enabled the speed response time constant is adjustable” Which is the register that changes the ‘speed response time constant’ I am unable to find such register.

Hi Surabibio,

Good question. I’ll see what I can find out about this. First thought (without research) - could it be that the slider shown in appnote actually controls one or more registers related to acceleration, but not named “xyz time constant”? Things like current limiting could affect this.

Hi David,
I tried tweaking Acceleration, PID_P, Accelerate_buffer, Decelerate_buffer but without luck. Maybe Allegro forgot to document this register and it is hiding in one of the undocumented registers??!