Drive circuit of stepping motor, integrated circuit thereof, and electronic equipment including same, and method for controlling drive circuit of stepping motor

Abstract

A drive circuit of a stepping motor includes a D/A converter, a current controller having a comparing unit, and an abnormality detecting unit. The DAC generates a target voltage indicating a target value for an excitation current determined based on a reference voltage indicating an upper limit value of the excitation current flowing into the stepping motor. The current controller controls the excitation current based on this target voltage. The comparing unit compares a voltage corresponding to the excitation current and the target voltage. The abnormality detecting unit detects an abnormality of the wire between the drive circuit and the stepping motor based on an output signal from the comparing unit and a control signal indicating a polarity of the excitation current.