Patent ID: 8339109
Filing Date: 2012-12-25
Classification: H02J

Abstract:
1. A charging circuit being integrated into a chip, comprising: a charging unit being connected to and between a power supply input and a load for outputting a constant current based on a constant voltage power supply supplied by the power supply input in order to charge the load; a switch unit being connected to and between the charging unit and the power supply input for turning on or cutting off the charging unit; a biasing unit being connected to the charging unit and the switch unit for supplying a first bias voltage to the charging unit; a voltage-dividing unit being connected at an end to the load and the charging unit for generating a first signal according to a voltage of the load; and a comparing unit being connected to the switch unit, the biasing unit and the voltage-dividing unit for receiving a second signal generated by the biasing unit and the first signal generated by the voltage-dividing unit, comparing the first signal with the second signal, and, based on a comparison result, outputting a second bias voltage to the switch unit for cutting off or turning on the switch unit, so that the charging unit is caused to charge or stop charging the load, respectively.