ZHCSH31B August 2017 – February 2018 DRV10987
The FG output frequency can be configured by FGcycle[3:0]. The default FG toggles once every electrical cycle (FGcycle = 0000). Many applications configure the FG output so that it provides two pulses for every mechanical rotation of the motor. The configuration bits provided in the DRV10987 device can accomplish this for 2-pole, 4-pole, 6-pole, and 8-pole motors up to 32-pole motors. This is illustrated in Figure 42 for 2, 4, 6, and 8-pole motors.
Figure 42 shows the DRV10987 device has been configured to provide FG pulses once every electrical cycle (4 poles), twice every three electrical cycles (6 poles), and once every two electrical cycles (8 poles).