摘要
文章介绍了两种CMOS带隙基准电路。它们在传统带隙基准电路的基础上,采用了低压共源共栅电流镜提供偏置电流,降低了功耗,减小了沟道长度调制效应带来的误差并使电路可以工作在较低的电源电压下;采用运放的输出作为共源共栅电流镜的偏置电压,使基准电压不受电源电压变化的影响。其中一种电路,还通过两个串联二极管的原理提高ΔVBE,从而减小了运放失调的影响。仿真结果表明,在工艺偏差、电源电压变化±10%以及温度在-20至125℃范围内变化的情况下,两种CMOS带隙基准的输出电压分别是1.228±0.003V和1.215±0.003V,温度系数仅为33.7ppm/℃和34.1ppm/℃;在电源电压分别大于2V和2.8V时,电源电压的变化对这两种基准的输出电压几乎没有影响;在3.3v电源电压下两个电路的功耗分别小于0.1mW和0.34mW。
Two types of CMOS bandgap reference circuits are presented in this paper.Based on the conventional bandgap reference,a low voltage cascode current mirror is used to produce bias currents and hence the errors resulted from the effect of the channel length modulation of PMOS are reduced.The bias voltage of the cascade current mirror is provided by an op -amp and hence the bandgap voltages are of supply independent.One of them is also able to decrease the effect of the op -amp offset by using dual diodes in serial to increaseΔV BE .The simulation results show that the output of the bandgap voltages are1.228±0.003V and1.215±0.003V respectively over the process,voltage and temperature variations,the temperature coefficient are only33.7ppm/℃and34.1ppm/℃respectively,the supply voltage has little influence on the output reference while it is above2v and2.8v;the dissipation of the circuits are less than0.1mW and0.34mW respectively,with the3.3v supply.
出处
《微电子学与计算机》
CSCD
北大核心
2003年第7期67-70,共4页
Microelectronics & Computer
基金
西安市科学技术计划基金资助项目(ZS200105)
