8.4.10.2 FG Open-Loop and Lock Behavior

Note that the FG output reflects the driving state of the motor. During normal closed loop behavior, the driving state and the actual state of the motor are synchronized. During open loop acceleration, however, this may not reflect the actual motor speed. During a locked motor condition, the FG output is driven high.

The DRV10983 provides three options for controlling the FG output during open loop as shown in Figure 37. The selection of these options is determined by the FGOLsel[1:0] setting.

• Option0: Open loop output FG based on driving frequency
• Option1: Open loop no FG output (keep high)
• Option2: FG output based on driving frequency at the first power-on start-up, and no FG output (keep high) for any subsequent restarts

Figure 37. FG Behavior During Open Loop