If the motor is stationary, the commutation must be initialized to be in phase with the position of the motor. The MCT8315A provides various options to initialize the commutation logic to the motor position and reliably start the motor.

• The align and double align techniques force the motor into alignment by applying a voltage across particular motor phases to force the motor to rotate in alignment with this phase.
• Initial position detect (IPD) determines the position of the motor based on the deterministic inductance variation, which is often present in BLDC motors.
• The slow first cycle method starts the motor by applying a low frequency cycle to align the rotor position to the applied commutation by the end of one electrical rotation.

MCT8315A also provides a configurable brake option to ensure the motor is stationary before initiating one of the above start-up methods. Device enters open loop acceleration after going through the configured start-up method.