低功耗双带隙结构的CMOS带隙基准源

摘要

随着片上系统的发展,带隙基准源精度和功耗的要求也越来越高.目前的高阶温度补偿方法在工艺兼容、设计复杂度和功耗上还存在一定的局限性.本文推导了一个新颖的电流模带隙基准电路在饱和区工作时的温度特性,并结合双带隙结构在输出支路上采用电流比例相减的方式实现有效的曲率补偿,从而实现了一个新颖的双带隙结构CMOS带隙基准源.在GSMC 0.18 μm工艺下,设计的CMOS带隙基准源版图面积为0.066 mm2.蒙特卡罗后仿真的结果表明,在-40~125 ℃温度范围内平均温度系数为14.27 ppm/℃;在27 ℃时基准电压平均值为1.201 V,标准偏差变化仅为33.813 mV(2.82%);在3.3 V工作电压下,静态电流平均为9.865 μA,电源抑制为-37.21 dB.本文设计的带隙基准源具有高精度、低功耗、结构简单的特点,是片上系统的良好选择.%With the development of system on chip (SOC),the precision and power consumption requirements of bandgap reference are becoming more stringent.Until now,high order temperature compensations still have some restrictions in the process compatibility,design complexity and power consumption.In this paper,the temperature characteristic of a new current mode bandgap reference operating in saturated region is derived,and effective curvature compensation is implemented by current ratio subtraction in the output branch circuits with double bandgap structures.Thus,a new CMOS bandgap reference of double bandgap structures is implemented.Layout area of the bandgap reference is 0.066 mm2 in GSMC 0.18 μm process.The results of Monte Carlo post-simulations show that the average temperature coefficient is 14.27 ppm/℃ in the temperature range from -40~125 ℃,and the average reference voltage is 1.201 V at 27 ℃.The average static current is 9.865 μA and the power supply rejection is -37.21 dB at 3.3 V operating voltage.The bandgap reference designed in this paper has the characteristics of high precision,low power consumption and simple structure,which indicates that it is a better choice for SOC.