AMIS-30623 Datasheet, PDF (33/65 Pages) AMI SEMICONDUCTOR – LIN Microstepping Motordriver

AMIS-30623
14.3 Motor Driver
14.3.1. Current Waveforms in the Coils
The figure below illustrates the current fed to the motor coils by the motor driver in half-step mode.
Ix
Iy
Coil X
t
Coil Y
PC20051205.1
Figure 20: Current Waveforms in Motorcoils X and Y in Halfstep Mode
Whereas the figure below shows the current fed to one coil in 1/16^th micro stepping (1 electrical period).
Ix
Iy
Coil X
t
Coil Y
PC20051123.4
Figure 21: Current Waveforms in Motorcoils X and Y in 1/16^th Microstep Mode
14.3.2. PWM Regulation
In order to force a given current (determined by Irun or Ihold and the current position of the rotor) through the motor coil while ensuring
high energy transfer efficiency, a regulation based on PWM principle is used. The regulation loop performs a comparison of the sensed
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