AMIS-30621 LIN Micro-stepping Motor Driver
Data Sheet
14.3 Motor Driver
14.3.1. Current Waveforms in the Coils
Figure 19 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 19: Current Waveforms in Motor Coils X and Y in Half-step Mode
Where as Figure 20 shows the current fed to one coil in 1/16th micro-stepping (1 electrical period).
Ix
Iy
Coil X
t
Coil Y
PC20051123.4
Figure 20: Current Waveforms in Motor Coils X and Y in 1/16th Micro-step 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
AMI Semiconductor – Sept. 2007, Rev 1.5
32
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