| 摘要 |
<P>PROBLEM TO BE SOLVED: To mute a sound of motor drive when a power supply voltage is dropped. <P>SOLUTION: This motor drive circuit comprises a plurality of source-side transistors that discharge drive currents to a coil, a plurality of sink-side transistors that suck the drive currents from the coil, and a control circuit that selectively operates the plurality of source-side transistors and the plurality of sink-side transistors in order to switch directions of the currents flowing to the coil. The motor drive circuit also comprises a detection circuit that detects whether the power supply voltage is lower than a prescribed voltage or not; and a voltage limit circuit that lowers the voltage of the coil at a side where the drive currents are discharged below a voltage generated by the power supply voltage, on the basis of the detection result of the detection circuit that indicates that the power supply voltage is lower than the prescribed voltage. <P>COPYRIGHT: (C)2007,JPO&INPIT |
