Patent ID: 7579899

Claim:
A temperature detection circuit comprising: a temperature dependent voltage generation circuit for generating a temperature dependent voltage dependent on the temperature of a measurement object; a bandgap circuit for generating a temperature independent voltage independent of the temperature of the measurement object; and a comparator circuit for comparing the temperature dependent voltage generated in the temperature dependent voltage generation circuit with the temperature independent voltage generated in the bandgap circuit, and for outputting a temperature detection signal indicative of the high-low relationship between the temperature dependent voltage and the temperature independent voltage based on the comparison result, wherein the bandgap circuit includes: an N-channel transistor, source of which is connected to an input terminal of the comparator circuit and supplies a current having a positive temperature characteristic; and a control circuit for driving gate of the N-channel transistor so that the source potential of the N-channel transistor is made to have a constant potential independent of the temperature of the measurement object.