Patent ID: 8513923

Claim:
A battery charging control circuit, comprising: a connection jack configured for receiving a power supply; a charging module configured for charging a battery, wherein, the charging module comprises a limit current control pin providing a constant voltage; a current detection circuit configured for detecting a charge current to the battery, and providing a detection voltage proportional to the charge current; an amplifier circuit configured for amplifying the detection voltage and providing an amplified detection voltage, a comparison module configured for comparing the amplified detection voltage with a reference voltage, and outputting a switch signal when the amplified detection voltage is lower than the reference voltage; and a control module configured for controlling the charging module to charge the battery with a trickle current in response to the switch signal; wherein, the control module comprises a first branch and a second branch which are connected in parallel between the limit current pin of the charging module and a ground, the first branch includes a resistor having a first resistance value, the second branch includes a resistor and a high voltage activated switch which are connected in series, the resistor of the second branch has a second resistance value smaller than the first resistance value, the high voltage activated switch has a gate connected with the output port of the comparison module.