摘要
为了降低带隙基准的温度系数,提高电源抑制比(PSRR),设计了一种具有高阶温度补偿的高PSRR带隙基准.提出了一种基于双极性晶体管(BJT)温度系数工作的曲率补偿电路,产生高阶温度系数为正的补偿电流,对传统带隙基准中BJT的高阶温度系数进行补偿,使带隙基准实现更低的温漂特性.同时使用了内建电压源的结构,利用负反馈提高带隙基准的PSRR.基于SMIC 0.18 μm BCD工艺,完成了电路的设计.仿真结果表明,所设计的带隙基准在-40～125 ℃的温度范围内,温度系数仅为0.43×10-6/℃;同时,低频时的PSRR为-95.1 dB.
Abstract
To reduce the temperature coefficient of the bandgap reference and enhance its PSRR,a high PSRR bandgap reference was designed with high-order temperature compensation.A curvature compensation circuit was proposed based on the temperature coefficient of a BJT.This circuit generates a current with a positive high-order temperature coefficient to compensate for the high-order temperature coefficient of the BJT in the traditional bandgap reference.This allows the bandgap reference to achieve lower temperature drift characteristics.Meanwhile,a built-in voltage source structure was used to improve the PSRR of the bandgap reference by negative feedback.Based on the SMIC 0.18 μm BCD process,the designed circuit was made.Simulation results show that the designed bandgap reference has a temperature coefficient of only 0.43 × 10-6/℃ from-40 to 125 ℃,and the PSRR is-95.1 dB at low frequency.
维普
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