Patent ID: 7969227

Claim:
A temperature detection circuit comprising a first temperature detection circuit section including a first temperature sensor, and a second temperature detection circuit section including a second temperature sensor and insulated from the first temperature detection circuit section, wherein: the first temperature detection circuit section further comprises: a first comparison circuit configured to output a first square wave; a first integration circuit configured to integrate the first square wave to output a first triangular wave; a second comparison circuit configured to compare the first triangular wave with a temperature value obtained from the first temperature sensor to output a first PWM signal; and a first insulation circuit configured to insulate the first PWM signal to output a second PWM signal corresponding to the first PWM signal, the second temperature detection circuit section further comprises: a second insulation circuit configured to insulate the first square wave to output a second square wave corresponding to the first square wave; a second integration circuit configured to integrate the second square wave to output a second triangular wave; a third comparison circuit configured to compare a temperature value obtained from the second temperature sensor with the second triangular wave to output a third PWM signal; and a third insulation circuit configured to insulate the third PWM signal to output a fourth PWM signal corresponding to the third PWM signal, and the temperature detection circuit further comprises arithmetic means for calculating a higher one of the temperatures detected by the first and second temperature sensors based on the second and fourth PWM signals output by the first and third insulation circuits, respectively.