A 40 nW CMOS-based temperature sensor with calibration free inaccuracy within ±0.6◦c

Abstract

In this study, a temperature equivalent voltage signal was obtained by subtracting output voltages received from two individual temperature sensors. These sensors work in the subthreshold region and generate the output voltage signals that are proportional and complementary to the temperature. Over the temperature range of −40◦C to +85◦C without using any calibration method, absolute temperature inaccuracy less than ±0.6◦C was attained from the measurement of five prototypes of the proposed temperature sensor. The implementation was done in a standard 0.18 µm CMOS technology with a total area of 0.0018 mm2. The total power consumption is 40 nW for a supply voltage of 1.2 V measured at room temperature.