| 摘要 |
PROBLEM TO BE SOLVED: To provide a two-power supply type power supply device for a load drive unit with a simple structure capable of being stably operated. SOLUTION: Upon start-up, a power supply voltage Vl for a load drive circuit which a power supply circuit 5 for a load drive circuit applies to a load drive circuit 2, starts up later than a power supply voltage Vc for a control circuit which a power supply circuit 6 for a control circuit applies to a control circuit 3. Upon fall, the power supply voltage Vl for a load drive circuit which the power supply circuit 5 for a load drive circuit applies to the load drive circuit 2, and falls earlier than the power supply voltage Vc for a control circuit which the power supply circuit 6 for a control circuit applies to the control circuit 3. The delayed start-up operation and early fall operation of the power supply voltage Vl are achieved by the fact that an external power supply voltage Vdd is applied to the power supply circuit 5 for a load drive circuit through a constant-voltage diode 54. COPYRIGHT: (C)2007,JPO&INPIT
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