Patent ID: 7592778

Claim:
A battery protection IC chip, comprising: a protection section for protecting a battery during charging and discharging; and a temperature detector for detecting an ambient temperature, the temperature detector including a diode and an inverter having a threshold SH based on a predetermined temperature T 1 and a negative temperature characteristic of the diode, wherein the diode is connected to an input of the inverter via a resistance, and when the temperature of the diode is lower than the predetermined temperature T 1 , an input voltage of the inverter is above the threshold SH and an output of the inverter is low L because of the negative temperature characteristic of the diode, and when the temperature of the diode is higher than the predetermined temperature T 1 , the input voltage of the inverter falls below the threshold SH and the output of the inverter is high H because of the negative temperature characteristic of the diode; wherein the protection section is configured to turn off a charge control FET chip and a discharge control FET chip in response to a detection by the temperature detector indicating that the output of the inverter is high H.