A High Precision CMOS Temperature Detector with Curvature Calibration Technique

This paper introduces a high precision Complementary Metal Oxide Semiconductor (CMOS) temperature detector using curvature calibration technique. A calibration scheme is proposed to calibrate the temperature characteristics of the triode base-emitter voltage (V
BE
) using a resistor with positive temperature coefficient and a resistor with negative temperature coefficient. The bipolar junction transistor (BJT) base-emitter voltage difference is used to produce a positive temperature coefficient. The quantity of the positive temperature coefficient and the quantity of the negative temperature coefficient generated by the V
BE
are subtracted so that the resulting output temperature coefficient shows a large slope. In this paper, the loop with positive temperature coefficient and the loop with negative temperature coefficient share the branch of the same MOS and BJT, which makes the mismatch small and exhibit high precision. This circuit is designed in 180nm CMOS process. The simulation results show that the temperature curve of the corrected output current has a very high linear fitting degree of 0.9999 from -40°C to125°C.