一种基于新的偏置电路的低电压带隙基准电压源设计

Design of Low Supply Voltage Bandgap Voltage Reference with Novel Bias Circuit

通过设计带隙基准电压源中共源共栅电流镜的偏置电路以实现低电源电压工作。该偏置电路原理是利用一个始终工作在线性区的MOS管来使共源共栅电流镜的两个级联管均工作在饱和区边缘提高输出电压摆幅,从而降低电源电压。电路基于Chartered0.25μmN阱CMOS工艺实现,Hspice仿真结果与分析计算结果相符。基于这种偏置电路所设计的带隙基准电压源最低工作电压仅为2V,温度系数为12×10-5/℃,电源抑制在频率为1～10kHz时为-98dB,1MHz～1GHz时为-40dB。

This paper proposes a bias circuit for cascode current mirror in band-gap voltage reference to realize low supply voltage. The bias circuit using a MOS transistor which always operate in linear region to bias the two transistors of the cascode stage operating at the edge of saturation to improve the output voltage swing and subsequently low down the supply voltage. Prototype of the band-gap reference in this paper is fabricated using the 0. 25 /μm CMOS process of Chartered corp, and the simulation results using Hspice tools validate the strategy for designing the bias network. The minimum supply voltage of this reference is 2V, and the temperature coefficient is 12×10^-6/℃C and PSR is -98 dB in the frequency from 1 Hz to 10 kHz and -40 dB from 1 MHz to 1 GHz.