Patent ID: 8035346
Filing Date: 2011-10-11
Classification: H02J

Abstract:
1. A battery protection circuit for a rechargeable battery, the rechargeable battery comprising a positive voltage pin, a negative voltage pin, and a temperature sensing pin, a resistance of the temperature sensing pin varying with the temperature of the rechargeable battery, the battery protection circuit comprising: a temperature and voltage detection unit coupled between the positive voltage pin and the temperature sensing pin, and configured to determine the temperature of the rechargeable battery according to the resistance of the temperature sensing pin; and a discharging unit coupled between the positive voltage pin and the temperature and voltage detection unit; wherein the discharging unit is configured to discharge the rechargeable battery when the temperature of the rechargeable battery is higher than a predetermined temperature and stop discharging the rechargeable battery when a voltage of the positive voltage pin is lower than a first predetermined value, wherein the temperature and voltage detection unit comprises: a bias voltage unit coupled between the positive voltage pin and the temperature sensing pin, and configured to output a first voltage according to the resistance of the temperature sensing pin; and a voltage detection unit coupled between the bias voltage unit and the positive voltage pin, and configured to output a discharging signal to the discharging unit according to the first voltage and a voltage outputted from the positive voltage pin; wherein the discharging unit is configured to discharge the rechargeable battery in response to the discharging signal when the first voltage is lower than a second predetermined value.