Design of Temperature Sensor for Passive RFID System
According to the application requirements of passive RFID system,a high precision integrated temperature sensor chip is de-signed. A temperature sensor circuit architecture composed of temperature sensing circuit,PTAT bias current generation circuit and Sigma-Delta ADC is presented. The temperature detection circuit based on bipolar transistor is used to generate the voltage which is direct pro-portional to the temperature,and Sigma-Delta ADC is used to alternately quantize the voltage to obtain the digital quantity corresponding to the temperature. Chopping stabilization technology is adopted in the bias circuit to reduce the error caused by transistor mismatch and op-erational amplifier offset. The dynamic matching technology is adopted in the current mirror to eliminate the error caused by the current mirror mismatch. The circuit design and layout drawing of the temperature sensor are completed by using GSMC 0.13μm process,and the layout area is 420μm×350μm. The post simulation results show that the accuracy of the temperature sensor is -1.6 ℃/0.8 ℃ in the temperature range of-45℃～+85℃,and the resolution is 0.75℃. When the power supply voltage is 1.5 V,the current consumed by the temperature sensor is 0.253 mA.
temperature sensorchopper stabilization technologydynamic component matching technologysigma-delta ADCpassive RFID
万方数据
维普
