A Low Power Energy-Efficient Precision CMOS Temperature Sensor

This paper presents a low power, energy-efficient precision CMOS temperature sensor. The front-end circuit is based on bipolar junction transistors, and employs a pre-bias circuit and bipolar core. To reduce measurement errors arising from current ratio mismatch, a new dynamic element-matching mode is proposed, which dynamically matches all current sources in the front-end circuit. The first-order fitting and third-order fitting are used to calibrate the output results. On the basis of simulation results, the sensor achieves 3 sigma-inaccuracies of +0.18/-0.13 degrees C from -55 degrees C to +125 degrees C. Measurement results demonstrate sensor 3 sigma-inaccuracies of +/- 0.2 degrees C from 0 degrees C to +100 degrees C. The circuit is implemented in 0.18 m CMOS, and consumes 6.1 A with a 1.8 V supply voltage.