Patent ID: 8405359

Claim:
A battery protection IC for protecting a battery, comprising: a charge control signal output terminal for outputting a charge control signal which controls charging from a charger to the battery; a voltage monitoring circuit for monitoring a battery voltage of the battery, and detecting, when the battery voltage becomes equal to or higher than an overcharge detection voltage, that the battery voltage becomes equal to or higher than the overcharge detection voltage to output a detection signal; an output driver of a first conductivity type for being turned off to cut off a charge current when the detection signal is output; a charge control signal input terminal for receiving input of the charge control signal, the charge control signal input terminal being connected with a resistor in an outside thereof; a transistor of the first conductivity type for being turned off when a voltage of the charge control signal input terminal is pulled to a source voltage side by a voltage generated in the resistor, and being turned on when the charge control signal input terminal is opened or HIGH is input to the charge control signal input terminal; and a clamp circuit for clamping a gate voltage of the transistor to a predetermined voltage, the output driver being turned on when the transistor is turned off, and being turned off when the transistor is turned on to cut off the charge current.