lmd18245-mdc National Semiconductor Corporation, lmd18245-mdc Datasheet - Page 19

• Manufacturer Part Number: lmd18245-mdc
• Description: 3a, 55v Dmos Full-bridge Motor Driver
• Manufacturer: National Semiconductor Corporation

The Typical Application
QUARTER STEP DRIVE WITH TORQUE
COMPENSATION
Figure 14 shows the winding currents and lookup table for a
quarter step drive (four microsteps per full step) with torque
compensation.
Top Trace: Phase A Winding Current at 1A/div
Bottom Trace: Phase B Winding Current at 1A/div
Horizontal: 2ms/div
*250 steps/second
BRAKE A = BRAKE B = 0
FORWARD
REVERSE
|
|
FIGURE 14. Winding Currents and Lookup Table for Quarter Step Drive with Torque Compensation
90˚ ELECTRICAL/FULL STEP ÷ 4 MICROSTEPS/FULL STEP = 22.5˚ ELECTRICAL/MICROSTEP
REPEAT
112.5˚
135.0˚
157.5˚
180.0˚
202.5˚
225.0˚
247.5˚
270.0˚
292.5˚
315.0˚
337.5˚
22.5˚
45.0˚
67.5˚
90.0˚
0.0˚
|cos( )|
0.924
0.707
0.383
0.383
0.707
0.924
0.924
0.707
0.383
0.383
0.707
0.924
1
0
1
0
(Continued)
D A
15
14
14
15
14
14
11
11
11
11
6
0
6
6
0
6
DIRECTION A
19
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
01187826
|sin( )|
0.383
0.707
0.924
0.924
0.707
0.383
0.383
0.707
0.924
0.924
0.707
0.383
0
1
0
1
D B
11
14
15
14
11
11
14
15
14
11
0
6
6
0
6
6
DIRECTION B
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
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