Part Number:DRV8843
Is fPWM an externally applied signal? Or is it internally generated?
The datasheet implies externally applied in table 6.3 recommended operating conditions, but in table 6.5 electrical characteristics, fPWM is referred to as internal current control PWM frequency.
If the PWM frequency is fixed, does modulating the width affect the speed of the motor spin? Or does it affect the current applied to the motor coil?
There is a lot open for interpretation when it comes to the description of PWM in section 7.4.1 Bridge control. I am assuming the PWM signal applied at input AIN1 or 2 depending on slow or fast decay is externally generated. What do the inputs for AINx and BINx look like compared to the output for a full step sequence? Figures 9 and 10 show some information but not enough.
In the case of full step sequence, does the PWM signal get input to the AIN / BIN pins for a duration equal to the full step? and the "on time" before the PWM starts is the blanking time? or is this just a time set by the user to allow for a "soft start"? If there are any diagrams or scope captures that show the input signals and output signals for a longer duration of time (to show a few steps), this would be extremely helpful.
Are there any application notes or documents that would explain implementing the PWM for the stepper motor operation in more detail?