From the datasheet of DRV11873:
8.4 Device Functional Modes
8.4.1 Startup
At startup, commutation logic starts to drive the motor with one phase high, one phase low, and the third shut off.
If a zero-cross is detected on the shut off phase, commutation logic advances to the next step; the same phase
high, the shut off phase goes low, and the low phase is shut off. Initially, the BEMF is not strong enough to
detect the zero crossings, at this very initial stage the commutation switches automatically until the BEMF is large
enough to read. In startup mode, 100% duty cycle is applied regardless of PWM input. After the commutation
logic receives 4 continuous successful zero-crossings, it switches to normal operation.
Is there any specific parameters about the 'large enough BEMF', i.e., the BEMF detection threshold, may be X mV? what is the X value?
Thanks.
