Patent ID: 7420792

Claim:
A thermal protection circuit for an integrated circuit (IC) battery charger, the circuit comprising: a voltage regulated current source; an input reference voltage port for connecting to a voltage reference source to regulate an output current of the voltage regulated current source; a temperature sensor generating control signals at least in relation with a first predetermined temperature and a second predetermined temperature that is lower than the first temperature; a first controllable switch connecting the reference voltage port to an input of the voltage regulated current source, wherein the first switch opens by a control signal indicating a temperature at or above the first predetermined temperature and closes by a control signal indicating a temperature at or below the second predetermined temperature, and wherein at or below the second predetermined temperature the input of the voltage regulated current source reference input is connected to the input reference voltage; and a second controllable switch connecting the input of the voltage regulated current source to ground, wherein the second switch closes by a control signal indicating a temperature at or above the first predetermined temperature and opens by a control signal indicating a temperature at or below the second predetermined temperature, and wherein at or above the first predetermined temperature the input of the voltage regulated current source is connected to ground.