DRIVING CIRCUIT FOR STEPPING MOTOR, INTEGRATED CIRCUIT OF THE SAME, ELECTRONIC EQUIPMENT HAVING THE SAME, AND METHOD OF CONTROLLING THE DRIVING CIRCUIT FOR STEPPING MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a driving circuit for a stepping motor capable of detecting the abnormality in wires for supplying an excitation current to the stepping motor.;SOLUTION: A driving circuit 100 for a stepping motor 200 has a D/A converter 120, a current controller 130 including comparators 131 and 132, and an abnormality detector 170. The DAC 120 generates target voltages VA1 and VA2 representing target values for excitation currents IOUT1 and IOUT2 which are defined based on a reference voltage VREF representing an upper limit value of the excitation currents flowing in the stepping motor 200. The current controller 130 controls the excitation currents based on the target voltages. The comparators 131 and 132 compare voltages RNF1 and RNF2 corresponding to the excitation currents with the target voltages, respectively. The abnormality detector 170 detects the abnormality in wires between a driving circuit 100 and a stepping motor 200 based on output signals CLOUT1 and CLOUT2 from the comparators and control signals PHA1 and PHA2 representing polarities of the excitation currents.;COPYRIGHT: (C)2012,JPO&INPIT