设计了一种集成于无源UHF RFID标签芯片的新结构温度传感器。利用高PSRR共源共栅结构的电流镜偏置电路产生两路温度系数相反的电流,实现了偏置电流对电源电压和温度补偿。与温度相关的脉冲信号由类似差分的结构产生,有效的克服了工艺偏差导致的误差。计数时钟信号由标签内部振荡器提供,振荡器频率受偏置电流控制近似与电源电压和温度无关。采用SMIC 0.18μm 2P4M CMOS工艺,仿真结果表明:电源电压为1.8V,温度在-10℃~100℃变化时,偏置电流为112 nA,标签提供的时钟信号频率为2 MHz,温度传感器有效分辨率为0.5℃/LSB,工作电流为774 nA。
A new temperature sensor integrated in the passive UHF RFID tag is designed.Two currents with the opposite temperature coefficient are generated by making use of a cascode current mirror with high PSRR,to realize the supply voltage and temperature compensation.The pulse signal related to the temperature is generated by a similar differential architecture,it effectively overcomes the errors caused by process variation.The counting clock signal is provided by the local oscillator of the tag.And the oscillator frequency controlled by the bias current is approximately independent of the supply voltage and temperature.It is implemented in SMIC 0.18μm 2P4M CMOS process,as shown in the simulation results,when the supply voltage is 1.8V and temperature ranges from-10 ℃ to 100 ℃,the bias current is 112nA,the oscillator frequency of the tag is 2MHz,and the temperature sensor achieves an effective resolution of 0.5 ℃/LSB,the working currents are 774nA.