Datasheet

LMD18245

www.ti.com

SNVS110E –APRIL 1998–REVISED APRIL 2013

Table 2. Lookup Table for Half Step Drive with Torque Compensation

α |cos(α)| D A DIRECTION A |sin(α)| D B DIRECTlON B

| 0° 1 15 1 0 0 1

FORWARD 45° 0.707 11 1 0.707 11 1

↓ 90° 0 0 0 1 15 1

135° 0.707 11 0 0.707 11 1

180° 1 15 0 0 0 0

↑ 225° 0.707 11 0 0.707 11 0

REVERSE 270° 0 0 1 1 15 0

| 315° 0.707 11 1 0.707 11 0

REPEAT

QUARTER STEP DRIVE WITH TORQUE COMPENSATION

Figure 20 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

90° ELECTRICAL/FULL STEP ÷ 4 MICROSTEPS/FULL STEP = 22.5° ELECTRICAL/MICROSTEP

Figure 20. Winding Currents for Quarter Step Drive with Torque Compensation

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