| 摘要 |
PURPOSE:To reduce the unrequired power consumption from the memory power supply to the utmost, by backing up the power from the separate memory power supply from the applied voltage to the main circuit for the memory circuit, in the circuit providing main circuit and memory ciruit. CONSTITUTION:The voltage of the power supply 23 is set greater than that of the power supply 24, and when the power supply switch 25 is closed, the diode D35 is biased reverse, and the voltage between the collector and emitter of the transistor TR28 is decreased nearly zero. Accordingly, since almost equal power supply voltage is fed to the first circuit 21 and the second circuit 22, normal operation is obtained. Next, when the switch 25 is open, the voltage subtracting the forward voltage drop of D35 from the DC sub-power supply 24 is fed to the first circuit 21 and the information of the first circuit 21 is kept holding as a result. In this case, no current flows from the base to the collector of TR28, and the leakage current from the emitter to the collector of TR28 can not almost flow. |
