Switched Capacitor Circuit Realization of Sigma-Delta ADC for Temperature Sensor

In this article the basic operating principles of CMOS smart temperature sensors are demonstrated. In this article a CMOS temperature sensor with sigma-delta analog to digital converter (ADC) is proposed, which have widespread use due to their low cost, low power consumption and small size. The sigma-delta ADC was implemented by the switch capacitor circuit. For the implementation of sensor high-performance signal conditioning circuits are required as interfacing circuit and for these bias circuits have been designed. The accuracy of sensor is mainly limited by offset and 1/f noise, which is canceled by the autozeroing circuit with the help of switch capacitor circuit. The sensor circuit is designed with biasing subcircuit for controlling the curvature correction.