THERMAL SENSOR CIRCUIT AND CALIBRATION METHOD USING THE SAME

A thermal sensor circuit that includes a temperature sensing circuit, an analog to digital converter, a processor, a divider circuit and a digital circuit is introduced. The temperature sensing circuit generates first and second temperature-dependent voltages. The digital to analog converter converts the first and second temperature-dependent voltages to first and second bit streams. The processor generates a third bit stream based on a thermal coefficient. The divider circuit divides one of the first and second bit streams by a denominator value to generate a fourth bit stream, wherein the denominator value is determined according to a bit value of the third bit stream. The digital circuit subtracts the other one of the first and second bit streams from the fourth bit stream to generate an output bit stream. The processor tunes the thermal coefficient until the output bit stream is equivalent to a bit stream of a reference model.