Patent ID: 7885044

Claim:
A motor drive device comprising: an Hall element; a control input terminal configured to receive a control signal instructing rotation of a motor to be driven, the control signal being variable between a state to instruct stoppage of the motor and a state to instruct driving of the motor; a pulse width modulator configured to generate a PWM signal based on the control signal from the control input terminal and a signal from an oscillator; a drive unit configured to control energization of the motor based on a signal from the Hall element and the PWM signal; a lock protection circuit configured to monitor a signal indicating a present rotational condition of the motor and to stop energization of the motor, when rotation of the motor is stopped; a lock controller configured to have the lock protection circuit inactive, in cases in which the control signal continues to instruct stoppage of the motor for at least a predetermined first time-period, the predetermined first time-period being measured from a time at which the control signal transitions from the state to instruct driving of the motor to the state to instruct stoppage of the motor; and a standby controller configured to start time measurement at an occasion when the control signal has continued to instruct stoppage of the motor for at least the first time-period, and after a further predetermined second time-period has elapsed, to stop at least part of the motor drive device, and to make the motor drive device transit to a standby mode.