| 摘要 |
<p>PURPOSE:To simplify the constitution and reduce the substrate occupation area by composing the device of a reset signal generation part, a memory power source switching signal generation part, a backup battery, and a memory power source switching part. CONSTITUTION:An operating voltage Ei which is generated at the same time with AC input is applied to the reset signal generation part 1, memory power source switching signal generation part 2, and memory power source switching part 4, which are activated. The signal generation part 1 outputs a reset pulse Pr on inputting a voltage VCC control logic operation and the signal generation part 2 outputs a switching signal Sc from both the ends of a resistance R through a constant voltage element Dz. The power source switching part 4 switches the backup voltage Eb of a backup battery 3 to the operating voltage Ei by inputting the signal Sc and outputs it as a memory source voltage. In this constitution, the signal generation part 2 is composed of the series circuit of the element Dz and resistance R, so the constitution is simplified and the substrate occupation area is reducible.</p> |
