Design of High-Performance Temperature Sensor Module for Internal Compensation in ASIC Chips

The design of temperature compensation can create a dependable and consistent working environment for high-precision Application Specific Integrated Circuit (ASIC). This article presents the design of a temperature sensor module that is suitable for internal temperature compensation in chips. The external working temperature is converted from temperature signal to electrical signal by PTAT circuit linearly related to temperature. PTAT circuit adopts a self-starting design without the need for additional control signals. The 16-bit SAR ADC replaces the traditional Sigma-delta ADC, reducing the conversion time to the microsecond level. The DAC adopts a three-stage structure design, and the use of unit capacitors reduces by 99.71%. Using SMIC 180nm CMOS process, simulation results show that stable conversion can be achieved in the temperature range of -40 ~ 85C at a working voltage of 5V, and the voltage-temperature response is 20.8mV/°C. At a sampling frequency of 100K, the SAR ADC simulation yields SNDR of 90.5dB, SFDR of 98.96dB, ENOB of 14.90bits, and SAR ADC’s optimal FoMs of 153.1dB. The circuit total power consumption is 27.8mW. The result shows that the temperature sensor achieves a temperature resolution of 0.008°C.