A CMOS temperature sensor and auto-zeroing circuit with inaccuracy of −1/+0.7 °C between −30 to 150 °C

Abstract

An energy efficient complementary metal-oxide-semiconductor (CMOS) temperature sensor and signal conditioning circuit with auto zeroing technique has been enunciated in this paper. In the present study, a novel CMOS temperature sensor based on sub-threshold MOS operation has been presented, which is designed for Aerospace applications. The proposed sensor does not use bipolar junction transistor (BJT) for sensing; instead it utilizes the temperature dependency of the threshold voltage of MOSFET. The proposed temperature sensor is designed to sense −30 to 150 °C and its sensitivity is 1.4 mV/°C while the power consumption is 60 nW. The accuracy of sensor is mainly limited by offset and flicker noise (1/f) noise, which is cancel by the autozeroing circuit with the help of switch capacitor circuit. The sensor circuit is designed with biasing sub circuit for controlling the curvature correction. The proposed temperature sensor and signal conditioning are simulated in a Cadence Analog Design Environment with UMC90 nm library. The simulation result shows an inaccuracy of −1/+0.7 °C.