Patent ID: 8242747
Filing Date: 2012-08-14
Classification: H02J

Abstract:
1. A charging control circuit for controlling charging of a secondary battery, the charging control circuit comprising: a charging transistor to generate a charging current according to a control signal input to a control electrode and to output the charging current to the secondary battery; a proportional current generation transistor to generate and output a proportional current proportional to the charging current output by the charging transistor according to the control signal; and a constant current charging controller to control the charging transistor so that the proportional current generated by the proportional current generation transistor attains a predetermined first value, the constant current charging controller including an operational amplifier comprising input terminals for receiving input voltages from current output terminals of the charging transistor and the proportional current generation transistor, respectively, and controlling a voltage of the current output terminal of the proportional current generation transistor to maintain a voltage difference between the current output terminal of the proportional current generation transistor and the current output terminal of the charging transistor at a predetermined second value.