Accurate operation of a CMOS integrated temperature sensor

A high-accuracy temperature sensor is designed by applying the temperature characteristics of substrate bipolar transistor in CMOS technology. Initial accuracy of the temperature sensor can be improved by chopper amplifiers and dynamic element matching. Using these two methods, the circuit realization of reference voltage is also described. Simulation results show that the inaccuracy is within×0.4 °C from −40 to +100 °C. Experimental results, obtained from circuits fabricated in 0.5 μm CMOS process, indicate that the sensor is inaccurate within×0.7 °C from −40 to +100 °C. The power dissipation is 0.35 mW and the chip area is 889 μm×620 μm. Compared with previously reported work, the temperature sensor in the paper has lower inaccuracy without calibration.