| 摘要 |
<p>PURPOSE:To use a small-capacity hold capacitor to supply the power to a circuit including a central processing part for a long time by limiting circuits, to which the power can be supplied from the hold capacitor at the time of a momentary break of power, to circuit parts having light loads. CONSTITUTION:A first supply voltage Vcc1 supplied to a first circuit part 3 which includes a signal input/output part and has a heavy load is reduced through a Schottky diode D1. The reduced supply voltage is held by a hold capacitor C2, and a second obtained supply voltage Vcc2 is supplied to a second circuit part 2 which includes the central processing part and has a light load. If a momentary break of the first supply voltage Vcc1 occurs, power supply to the first circuit part 3 is stopped, but supply of the second supply voltage Vcc2 from the hold capacitor C2 to the second circuit part 2 is continued. Thus, the circuit to which power is supplied from the hold capacitor C2 at the time of a momentary break of power is limited to the second circuit part 2 having a light load.</p> |
