Design of a Temperature Sensor Based on Auto-Zero Technology

A Complementary Metal Oxide Semiconductor (CMOS) temperature sensor using auto-zero technology was designed based on the CMOS 55 nm process. The sensor consists of a temperature detection module and an analog-to-digital converter (ADC) module. The temperature detection module uses bipolar transistors (BJT) as temperature sensing devices, and the ADC adopts a Sigma-Delta/Cyclic hybrid architecture. In order to achieve accurate quantification of the output signal, auto-zero technology is used to minimize the measurement accuracy degradation caused by the offset voltage of the operational amplifier (op-amp). The simulation results show that under a 2.5 V power supply and a 50 kHz clock input, the temperature sensor achieved 16 bit temperature measurement results within 30 ms conversion time, with a maximum inaccuracy of ± 0.25°C, and achieved a temperature resolution of 4m°C in the temperature range of -45 to 125°C.