低温漂高抑制比带隙基准电压源设计

Design of a Low Temperature Drift and High PSRR Bandgap Reference Voltage Source

采用含运算放大器钳位结构的带隙基准核心电路,设计一种低温漂系数高抑制比带隙基准电压源。针对基准核心电路输出电压中高阶温度分量对温漂系数的影响,加入了一种电流抽取与注入结构的高精度曲率校正电路,在基准输出电压随温度上升而增大阶段抽取一部分正温度系数电流,在基准输出电压随温度上升而减小阶段注入一部分正温度系数电流,利用单一的正温度系数电流对基准输出电压高阶温度分量进行校正,达到降低温漂系数的目的。在0.5μm CMOS工艺模型下,使用Cadence Spectre软件对电路进行仿真,仿真结果表明,温度特性得到了较大的改善,当温度在-40～+125℃范围内时,温漂系数仅为0.5057×10-6/℃,低频段时电源抑制比为-81.8 d B。带隙基准电路正常工作的最低电源电压为2.4 V。

A bandgap reference core circuit with an operational amplifier clamp structure is used to design a bandgap reference voltage source of low-temperature-drift coefficient and high rejection ratio.Aiming at the problem that the high-order temperature component in the output voltage of the reference core circuit has an influence on the temperature drift coefficient,a high-precision curvature correcting circuit coupling with current extraction and injection structure is added.When the reference output voltage increases with the increase of temperature,the part of positive temperature coefficient current is extracted.when the reference output voltage decreases as the temperature rises,the part of positive temperature coefficient current is injected.The single positive temperature coefficient current is used to correct the high temperature component of the reference output voltage to reduce the temperature drift coefficient.Based on 0.5μm CMOS process model,the circuit is simulated by using Cadence Spectre software,and the simulation results show that the temperature characteristics have been greatly improved.When the temperature is in the range of-40^+125℃,the temperature drift coefficient is only 0.5057×10^-6/℃,and the PSRR is-81.8 dB at low frequency.The bandgap reference circuit can operate normally at a minimum supply voltage which is approximately 2.4 V.