基于CMOS阈值电压设计的电压基准源

Voltage reference based on CMOS threshold voltage

基于TSMC 0.18μm标准CMOS工艺,提出了一种新型无电阻低温漂电压基准源。通过采用CMOS阈值电压(Vth)和与温度成正比的电压(VPTAT)作为基础线性温度单元加权求和的方式,消除了电压基准源输出中残留的非线性温度分量,最终得到高精度的电压基准输出。其中CMOS阈值电压由无电阻结构产生,VPTAT的产生和与CMOS阈值电压的加权求和由非对称差分运放完成。实测结果证明,在-55℃~125℃温度范围内,电压基准源输出为1.23 V,温度系数为4.5 ppm/℃。在无滤波电容的情况下,基准电源抑制比可达-93 dB。

A novel low temperature coefficient voltage referece without resistors is presented in this brief,which is compatible with standard TSMC 0.18 μm CMOS technology.Threshold voltage(Vth) and proportional to absolute temperature voltage(VPTAT)form the basic linear temperature components.By weighting the sum of the two through asymmetric differential operational amplifier,the nonlinearity in the voltage reference is cancled and the precision of the output voltage is improved.The Vth is achieved by resistorless circuit and the VPTAT is achieved by asymmetric differential operational amplifier.The experimental results show that in the temperature range of-55 ℃ to 125 ℃,the voltage reference is 1.23 V with a temperature coefficient of 4.5 ppm/℃,and the power supply rejection ratio is lower than-93 dB while without filtering capacitor.