Battery charging circuit

摘要

The present disclosure illustrates a battery charging circuit, adapted for charging a rechargeable battery. The battery charging circuit includes a temperature sensing unit, a current control unit, and a charging unit. The temperature sensing unit is coupled to a temperature output pin of the rechargeable battery to output a temperature signal according to the sensed temperature of the rechargeable battery. The current control unit is coupled to the temperature sensing unit for outputting a control voltage according to the received temperature signal. The charging unit is coupled to the current control unit and outputs a charging current to charge the rechargeable battery. When temperature of the rechargeable battery exceeds a predefined temperature range, the charging unit discontinues outputting the charging current. Hence, the battery charging circuit can completely fulfill the charging requirement of the rechargeable battery thereby increase the associated charging efficiency.

主权项

1. A battery charging circuit, adapted for charging a rechargeable battery, comprising:
a temperature sensing unit, coupled to a temperature output pin of the rechargeable battery, outputting a temperature signal according to the temperature of the rechargeable battery, wherein the temperature sensing unit comprises: a first resistor, coupled between a power terminal and the temperature output pin; and a buffer, having a non-inverting terminal coupled to the temperature output pin through a second resistor and an inverting terminal coupled to an output terminal of which the temperature signal is outputted to the current control unit; a current control unit, coupled to the temperature sensing unit, outputting a control voltage according to the temperature signal; and a charging unit, coupled to the current control unit, the charging unit outputting a charging current charging the rechargeable battery according to the control voltage; wherein the charging unit discontinues outputting the charging current when the temperature of the rechargeable battery exceeds a predefined temperature range; the charging unit gradually increases the charging current according to the temperature of the rechargeable battery when the temperature of the rechargeable battery is higher than a minimum value of the predefined temperature range; the charging unit discontinues outputting the charging current when the temperature of the rechargeable battery is higher than a maximum value of the predefined temperature range.