PRINCIPLES OF OPERATION
SLA7020M Phase Signal Input Circuit
Although most stepper-motor control ICs input four-phase data directly, the SLA7020M requires a special
type of phase data. In the case of 2-2 phase excitation, Figure 2-47 shows the excitation signal input circuit.
The A-phase-side excitation signal input is via a single line. The output is divided among non-inverted
A-phase output and k-phase output passed through an inverter. Therefore, the A-phase output side will be
ON when the excitation input signal is HIGH. And the A-phase output side will be ON when the excitation
input signal is LOW. Figure 2-48 shows the timing chart for 2-2 phase excitation.
2-40
Figure 2-47. Phase Data Input Circuit (2-2 Phase)
Input
Input
Figure 2-48. Phase Signal Timing Chart (2-2 Phase)
REV.-A
LQ-510