DRIVE CIRCUIT FOR STEPPING MOTOR, INTEGRATED CIRCUIT FOR SAME AND ELECTRONIC DEVICE COMPRISING SAME, AND CONTROL METHOD FOR STEPPING MOTOR DRIVE CIRCUIT

摘要

A drive circuit (100) for a stepping motor (200) comprises a D/A converter (120), a current control unit (130) including comparison units (131,132), and an error detection unit (170). The D/A converter (DAC) (120) generates target voltages (VA1, VA2) indicating target values for excitation currents stipulated on the basis of a reference voltage (VREF) indicating the upper limit for excitation currents (IOUT1, IOUT2) flowing to the stepping motor (200). The current control unit (130) controls the excitation currents on the basis of the target voltages. The comparison units (131, 132) compare the voltages (RNF1, RNF2), which correspond to the excitation currents, with the target voltages. The error detection unit (170) detects errors in wiring between the drive circuit (100) and the stepping motor (200) on the basis of output signals (CLOUT1, CLOUT2) from the comparison units and control signals (PHA1, PHA2) indicating the polarity of the excitation currents.