A 62.6-pJ/Conversion Temperature Sensor with a Capacitor Voltage Division

This paper presents an ultra-low-power temperature sensor that detects the temperature with a leakage-based bandgap circuit and converts it with an asynchronous SAR ADC. The implemented temperature sensor consumes 487 pW at 20 degrees C with an energy efficiency of 62.6 pJ/conversion. A 1-point and 2-point calibrations show peak-to-peak inaccuracies of-3.43/+2.77 degrees C and-1.63/+1.63 degrees C, respectively, in a temperature range of-30-to-100 degrees C. The supply sensitivity is 0.61 degrees C/V at 20 degrees C.