| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit that can control a voltage between and among a plurality of power supplies not only at power input but also at power cutoff. SOLUTION: When a control signal of a microcomputer 108 is changed to a High level from a Low level, Vfb1 is controlled to be equal to Vref1 (Vfb1=Vref1), and Vfb2 is controlled to be equal to Vref2 (Vfb2=Vref2) by a step-down converter 102 and a step-down converter 120, and a reference voltage value Vref1 is controlled to be larger than a reference voltage value Vref2 (Vref1>Vref2). When the control signal of the microcomputer 108 is changed to the Low level from the High level, the potential Vcht1 of the cathode side of a diode D1 is controlled to be larger than the potential Vcht2 of the cathode side of a diode D2 (Vcht1>Vcht2) by using a proper voltage-dividing resistor. COPYRIGHT: (C)2006,JPO&NCIPI
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