| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the loss of a switching circuit while preventing an increase in cost required for the configuration. <P>SOLUTION: A PWM operation unit 25 capable of independently setting each on-duty of a high-side switching element and a low-side switching element determines whether a forward current does not flow through any of the high-side switching element and the low-side switching element on the basis of a load current flowing through a motor detected by a phase-current detection unit 32. A reverse-direction duty determination unit 25a determines that the on-duty of the switching element, which is determined that the forward current does not flow therethrough, is set to be zero when an absolution value of the load current or conduction loss of the forward current is more than or equal to a predetermined value. The PWM operation unit 25 sets the on-duty of the switching element, which is determined that the forward current does not flow therethrough, to be zero on the basis of the determination result of the reverse-direction duty determination unit 25a. <P>COPYRIGHT: (C)2013,JPO&INPIT |
