Motor alignment control

A motor drive system for use with a motor, comprising:

• a first high-side switch coupled to a high voltage bus and the motor;
• a first low-side switch coupled to the motor and a return,
• wherein a turn ON and turn OFF of the first high-side switch and the first low-side switch provides a phase current for the motor;
• and
• a system controller configured to receive a phase current sense signal representative of the phase current of the motor and further configured to begin an alignment sequence to align the motor to a goal alignment position, wherein
• during the alignment sequence at least one of the first high-side switch or the first low-side switch is turned ON and OFF under the control of an alignment duty ratio, and
• the system controller is configured to end the alignment sequence and begin a normal operation sequence in response to a sensed decrease in an envelope of the phase current sense signal,
• the system controller is configured to compare a sample of the phase current sense signal to a previous sample of the phase current sense signal to track the phase current sense signal and to determine a maximum value of the phase current, wherein
• the system controller is further configured to compare the maximum value of the phase current sense signal to the sample of the phase current sense signal to sense the decrease in the envelope of the phase current sense signal.