A high-precision CMOS temperature sensor with thermistor linear calibration in the (−5°C, 120°C) temperature range

Abstract

A high-precision Complementary Metal-Oxide-Semiconductor (CMOS) temperature sensor for (−5°C, 120°C) temperature range is designed and analyzed in this investigation. The proposed design is featured with a temperature range selection circuit so that the thermistor linear circuit automatically switches to a corresponding calibration loop in light of the temperature range besides the analysis of the calibration method. It resolves the problem that the temperature range of a single thermistor temperature sensor is too small. Notably, the output of the proposed design also attains a high linearity. The measurement results in a thermal chamber justifying that the output voltage is 1.96 V to 4.15 V, the maximum linearity error ≤1.4%, and the worst temperature error ≤1.1°C in the temperature range of −5°C to 120°C.