An Ultra-Low-Power Cmos Temperature Sensor For Rfid Applications

An ultra-low-power CMOS temperature sensor with analog-to-digital readout circuitry for RFID applications was implemented in a 0.18-mu m CMOS process. To achieve ultra-low power consumption, an error model is proposed and the corresponding novel temperature sensor front-end with a new double-measure method is presented. Analog-to-digital conversion is accomplished by a sigma-delta converter. The complete system consumes only 26 mu A @ 1.8 V for continuous operation and achieves an accuracy of +/- 0.65 degrees C from-20 to 120 degrees C after calibration at one temperature.