| 摘要 |
PURPOSE:To provide a power supply circuit, in which the damage due to an overcurrent is prevented in the event of a short circuit between a power supply line and a ground line, and circuit blocks are individually switched on and off for reducing power consumption. CONSTITUTION:A power supply circuit is composed of a control signal 34 on-off controlling a circuit block 6 by an output from a control block 3 with a device 1, an original power supply 2, a control block 3, a first switch circuit 4 turning a power supply line 6A on-off, and a circuit block 6 driven by a power supply fed from the power supply line 6A and a switch constituted of a transistor 51, a resistor 52 and a resistor 53, a feedback resistor applying a feedback from the power supply line 6A and being connected to the resistor 52 and the parallel circuit of a diode 57 inserted between the control signal 34 and the resistor 52 and a capacitor 56 in a second switch circuit 5 turning the first switch circuit 4 on-off. |
