EVAL6470H Datasheet, PDF (22/70 Pages) STMicroelectronics – dSPIN fully integrated microstepping motor driver with motion engine and SPI

Functional description
Figure 5. Charge pump circuitry
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Microstepping
The driver is able to divide the single step into up to 128 microsteps. Stepping mode can be
programmed by the STEP_SEL parameter in the STEP_MODE register (see Table 18).
Step mode can only be changed when bridges are disabled. Every time the step mode is
changed the electrical position (i.e. the point of microstepping sinewave that is generated) is
reset to the first microstep and the absolute position counter value (see Section 6.5)
becomes meaningless.
Figure 6. Normal mode and microstepping (128 microsteps)
2ESET
POSITION
.ORMALDRIVING
0(!3%!CURRENT
0(!3%"CURRENT
2ESET
POSITION
-ICROSTEPPING
0(!3%!CURRENT
0(!3%"CURRENT
MICROSTEPS
STEP STEP STEP STEP STEP
STEP STEP STEP STEP STEP




ª STEPS ª STEPS ª STEPS ª STEPS
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Doc ID16737 Rev 5