An Ultra-Low Power Time-Domain Temperature Sensor for IoT Applications

Abstract

This paper proposed an ultra-low power time-domain temperature sensor circuit for IoT applications. It uses 2- T structures to generate reference voltage and complementary-to-absolute-temperature (CTAT) voltage. The reference voltage produces reference current by using current mirror to charge the capacitor. Then the voltage of capacitor is compared with the CTAT voltage to generate a temperature-dependent pulse. The pulse width is then digitized to represent the temperature. The temperature sensor is designed using 0.1S $\mu$m CMOS process. The simulation results show that it measures temperature from −10°C to 60°C from 1V supply voltage. The power it costs is 570nW at a conversion speed of100 Sa/s.