Patent ID: 7928694
Filing Date: 2011-04-19
Classification: H02J,Y02E

Abstract:
1. A charging and discharging control circuit for controlling charging and discharging of a battery, comprising: a voltage divider circuit for dividing a voltage of the battery; a first reference voltage circuit for outputting a first reference voltage; a second reference voltage circuit for outputting a second reference voltage; an overcharge detecting comparator for comparing an output signal of the voltage divider circuit with the first reference voltage to detect an overcharged state of the battery; an overcurrent detecting comparator for comparing a voltage at an overcurrent detecting terminal with the second reference voltage to detect an overcurrent state of the battery; a control circuit for performing on/off control of each of the switch provided between one of a charger and a load and the battery, and of a protection circuit provided between a VSS terminal and the overcurrent detecting terminal, in response to an output signal from each of the overcharge detecting comparator and the overcurrent detecting comparator; and the protection circuit which is turned on in response to an output signal from the control circuit so as to connect a resistor to a path connecting the VSS terminal and the overcurrent detecting terminal, and which is turned off in response to the output signal from the control circuit so as to disconnect the resistor from the path.