| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery voltage detection circuit that can accurately detects a voltage of a battery at a time when the voltage is varied. SOLUTION: This battery voltage detection includes a first capacitor 10, an operational amplifier 12 having a non-inverting input terminal (+) of which keeps a reference voltage VREF applied, a second capacitor 11 which is connected across the output terminal of the operational amplifier 12 and the inverting input terminal (-) thereof, and a switch circuit. After the switch circuit respectively applies voltages of both terminals of batteries BV1 to BV4 to one terminal and the other terminal of the first capacitor 10, the switch circuit connects one terminal of the first capacitor 10 to the inverting input terminal (-) of the operational amplifier 12, and then it applies the reference voltage VREF to the other terminal of the first capacitor 10. The voltages of both terminals of the batteries BV1 to BV4 are detected on the basis of the output voltage VOUT of the operational amplifier 12. COPYRIGHT: (C)2011,JPO&INPIT |
