一种高精度CMOS带隙基准源的设计

Design of High Precision CMOS Bandgap Reference

分析了传统CMOS带隙基准源电路中三极管VBE电流随温度变化的二阶非线性效应，提出了一种对PTAT二阶温度进行补偿的方法，并在此基础上设计了一个高精度的带隙基准源电路。该电路采用SMIC 0．18μm CMOS工艺实现，具有良好的温度系数和电源抑制比。Cadence Spectre仿真结果表明，该电路在-40～140℃的温度系数为7．7×10^-6／℃，低频时的电源抑制比可达-76dB，基准源电路的供电电压范围为2～4．5V。

The second-order nonlinear effect of the transistor VSE current varying with temperature in the conventional CMOS bandgap reference was analyzed. A curvature compensation method for the proportion to absolute temperature （PTAT） was proposed and a high precision CMOS bandgap reference based on this method was designed. The bandgap referebce was implemented in SMIC 0.18 μm CMOS technology, which had a good temperature coefficient （TC） and a low power supply rejection ration （PSRR）. Cadence Spectre simulation result shows that the circuit has an accuracy of 7.7 ×10^-6/℃ at - 40 to 140 % and a power supply rejection ration of - 76 dB at low frequency. The circuit can operate at the range from 2 to 4.5 V.