一种高电源抑制比低温漂带隙基准电压源设计

Design of a Low Temperature Drift Bandgap Reference VoltageSource with High Power Supply Rejection Ratio

针对传统带隙基准电压源温度系数大、电源抑制比低等问题,设计了一种低温漂高电源抑制比的带隙基准电压源。将具有二阶温度项的亚阈值状态NMOS管漏电流转化为电压,以消除输出支路三极管的二阶温度项,实现二阶温度补偿;增加了一个前置的新型预稳压电路,以提高基准源的电源抑制能力。SMIC 180 nm CMOS工艺下的后仿真结果表明,当供电电压为3.3 V时,在-40~140℃,温度系数为3.05×10-6/℃;在低于1 kHz的频率范围内,电源电压抑制比(PSRR)为-105 dB,整体静态电流仅为32μA。

A bandgap reference voltage source with low-temperature drift and high power supply rejection ratio is designed for the problems of large temperature coefficients and low power supply rejection ratio of traditional bandgap reference voltage source.Firstly,Second-order temperature compensation is achieved by converting the subthreshold state leakage current of NMOS tubes with second-order temperature terms into voltage to eliminate the second-order temperature terms of the output branch triode.Secondly,a new type of pre-stabilized voltage circuit is added to improve the power supply rejection ability of the BGR.Simulation results using SMIC 180 nm CMOS technology show that the temperature coefficient is 3.05×10-6/℃at 3.3 V supply voltage when the temperature range is-40~140℃.The Power Supply Rejection Ratio(PSRR)is-105 dB within 1 kHz and the overall static current is only 32μA.