AMIS-30523 Datasheet, PDF (23/35 Pages) ON Semiconductor – CAN Micro-Stepping Motor Driver

1.48 A
Peak Current
AMIS−30523
Current Range 3
CUR[4:0] = 23 −> 31
630 mA
Current Range 2
CUR[4:0] = 16 −> 22
325 mA
166 mA
Current Range 1
CUR[4:0] = 9 −> 15
Current
Range 0
CUR[4:0] = 0 −> 8
0
8
15
22
31
Figure 19. Programmable Peak−Current Overview
CUR[4:0]
Speed and Load Angle Output
The SLA−pin provides an output voltage that indicates the
level of the Back−e.m.f. voltage of the motor. This
Back−e.m.f. voltage is sampled during every so−called ”coil
current zero crossings”. Per coil, two zero−current positions
exist per electrical period, yielding in total four zero−current
observation points per electrical period.
I_COIL
V_BEMF
t
Previous
Micro−Step
I_COIL
ZOOM
Coil Current Zero Crossing
Current Decay
Zero Current
Next
Micro−Step
t
V_COIL
V_BB
Voltage Transient
|V_BEMF|
t
Figure 20. Principle of Bemf Measurement
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