A CMOS based High Resolution All-Digital Temperature Sensor with Low Power Supply Sensitivity

Abstract

This paper presents the design of an All-Digital-Temperature Sensor (ADTS) with low power supply sensitivity (PSS). In this architecture, the delay cell-based ring-oscillator acts like a temperature sensor. The delay cells have been designed featuring the voltage compensation technique. This paper demonstrates the improvement over the conventional Current Starved Ring Oscillator (CSRO), and Voltage Compensated Ring Oscillator (VCRO) based temperature sensor. The proposed design consumes only 180μW power, exhibits PSS of 0.034°C/mV (i.e., 6-12%) and generates an error of only -0.4°C to +0.8°C across process comers and over the temperature range -40°C to 150°C and supply range of 1.8V +/-10%.