Patent ID: 8030866

Claim:
A motor drive circuit comprising: a first transistor and a second transistor connected in series, a voltage of a connection point between the first transistor and the second transistor being a drive voltage applied to one end of a motor coil; an operational amplifier configured to control the first transistor and the second transistor such that the drive voltage is a voltage according to a difference between a first control voltage and a second control voltage for controlling driving of the motor coil; a switch circuit configured to drive the first transistor and the second transistor such that the motor coil is in a state of not being driven regardless of control by the operational amplifier when a pulse signal for intermittently driving the motor coil is at one logic level, and drive the first transistor and the second transistor based on the control by the operational amplifier when the pulse signal is at the other logic level; and an auxiliary drive circuit configured to drive the first transistor and the second transistor to increase the drive voltage for a predetermined time period shorter than a time period during which the pulse signal is at the other logic level regardless of the control by the operational amplifier, when the pulse signal changes from the one logic level to the other logic level.