| 摘要 |
PURPOSE:To prevent the reception of the effect of temp. by setting off temp. coefficient, by providing first MOSFET wherein reference potential is applied to a gate and second MOSFET wherein a source and a drain are connected to each other. CONSTITUTION:A battery 10, P-channel type first MOSFET 3, P-channel type second MOSFET 4 wherein a gate and a drain are connected to each other ane N-channel type MOSFET 5 are connected between power source terminals VDD, VSS. Next, a fixed resistor 7 is connected between the source and drain of FET 5 in parallel and connected to an inverter 8 through a protective resistor 6. The second FET 4 having a drain and a gate connected thereto has negative temp. coefficient in a low potential side and sets off the positive temp. coefficient possessed by the first FET 3 and the divided voltage of the off-set temp. coefficient and thefixed resistor 7 is compared with the threshold value of the inverter 8. By this method, the life of the battery can be detected without receiving the effect of temp.
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