| 摘要 |
PURPOSE:To eliminate the cause of malfunction of a memory by providing a large capacitance capacitor in parallel with a small power backup battery for long service life so as to reduce the battery load at backup. CONSTITUTION:An external power supply is connected to an external power supply terminal 1 and applied to a memory IC9 via diodes D1, D2. The backup battery (e.g., lithium battery) 6 is connected to the memory IC9 via a diode D3 and the circuit is constituted heat the power is supplied from the battery 6 when the external power is failed. In this case, the large capacitance capacitor 3 is provided in parallel with the battery 6 between the diodes D1 and D2. Thus, if the external power is stopped, the power failure processing of the IC9 or the like is performed by a voltage charged in the capacitor 3. |
