| 摘要 |
PURPOSE:To prevent the wasteful power consumption of a battery for backup by obviating operation as a backup power supply of an element or a circuit of the battery for backup by a switch circuit before another power supply is applied to the element or the circuit. CONSTITUTION:When supply voltage VCPU1 or VCPU2 is made to rise from a stabilized power circuit 22 or a DC-DC converter 25, pulses RS are acquired at the node of a resistor 27 and a capacitor 28, thus correctly resetting an IC 20. When the IC 20 is reset, one output signal SW of the IC 20 is changed from a low level to a high level. Since the base of a transistor 32 is supplied with the signal SW through an inverter 34, the transistor 32 is turned ON, and a battery 31 for backup is brought to the state in which the battery 31 starts operation as the backup power supply of the IC 20. |
