一种低温度系数的带隙基准电压源设计

摘要

基准电压源是集成电路系统中的重要组成部分,其性能直接影响系统的稳定性和鲁棒性。温度系数是基准电压源的重要性能指标之一,而高阶温度补偿技术是降低基准源温度系数的有效方法。基于标准0.18μm CMOS工艺,设计了一种低温度系数的带隙基准电压源,采用电流模结构的带隙基准电路实现了低电源电压工作,并通过VBE线性化补偿技术实现了在低压下的高阶温度补偿。所设计的 CMOS 带隙基准电压源在-40~125℃的范围内,温度系数为6.855 ppm/℃,低频时电源电压抑制比达到了-95 dB,而电源电压在0.6~1.8 V范围内变化时线性调整率仅为0.2%。仿真实验结果表明,该电路结构能够有效提升带隙基准电压源的温度性能。%The reference voltage source is an important part of the integrated circuit system,and it has a direct impact on the stability and robustness of the system. The temperature coefficient is one of the important performances of the reference voltage source,and the high-order temperature compensation technology is an effective way to reduce the temperature coefficient. A bandgap voltage reference with a low temperature coefficient is designed based on standard 0. 18μm Complementary Metal Oxide Semiconductor ( CMOS) process. The current mode structure is used to make the circuit working under the low power supply voltage,and the linear compensation technology is applied to complete the high order temperature compensation. The designed voltage reference gives a good low temperature coefficient of 6. 855 ppm/℃ in the temperature range from-40 to 125 degree,and provides a good Power Supply Rejection Ratio (PSRR) of-95 dB in the low frequency band. The voltage linear regulation of the bandgap voltage reference is only 0. 2% while the supply voltage changes from 0. 6 V to 1. 8 V. The simulation results show that the circuit structure can improve the temperature performance of the bandgap refer-ence voltage source effectively.