DRV8711: Tuning Steps, How to Setup Suitable Configurations and Get a Nice Sinusoidal Current Waveform

Questions:

1. How to achieve a low noise performance of stepper?
   1. What impacts noise of a running stepper?
   2. Which drv8711 driver configurations impact noise?
2. How to achieve a minimal vibration performance of a stepper?
   1. What causes vibration of a running stepper?
   2. Which drv8711 driver configurations impact vibration?
3. Are the below current waveforms expected?
   1. Do higher frequencies cause triangular/square current waveforms?
   2. Can we set configurations such that the current waveforms are sinusoidal for all ranges of speed (1Hz to 250kHz)?
4. For accelerating and decelerating the stepper, do we need a non-zero starting speed and stopping speed?
   1. Why?
5. Why powering on motor (setting enable on CRTL Register of DRV8711) makes the motor jump/jerk?
   
   

My setup configuration is as follow:

1. Stepper Motor: Bipolar Stepper Motor Frame Size 23 200.0 Step 2.8 A 24VDC
2. Power Supply: 48V
3. DRV8711EVM board
4. Using most of the recommended settings from DRV8711 Quick Spin and Tuning Guide: 
   
   • Register Hex Value Settings
   • 0x01 Torque 0x0180  Torque = 80
   • 0x02 Off 0x0032 Internal indexer, 25 µs off time
   • 0x03 Blank 0x0100 Adaptive blanking, 1-µs current blanking
   • 0x04 Decay 0x0510 Use auto mixed decay, mixed decay time has no effect.
   • 0x05 Stall 0x0A02 BEMF/8, Stall after 2, approximately 20 mV (without experimentation yet)
   • 0x06 Drive 0x0000 Minimal drive, minimum OCP deglitch and threshold
   • 0x00 Control 0xxxxx 850 ns dead time, gain of 10, internal stall detect, 1/128 step, enable motor

One winding current waveform are measured below at varying indexing speeds:

Period = 1000 us

Period = 100 us

Period = 10us