关键词: 带隙基准电压源, 曲率补偿, 低温漂系数, 电流抽取, 电流注入

Abstract: A bandgap reference core circuit with an operational amplifier clamp structure is used to design a bandgap reference voltage source of low-temperature-drift coefficient and high rejection ratio.Aiming at the problem that the high-order temperature component in the output voltage of the reference core circuit has an influence onthe temperature drift coefficient,a high-precision curvature correcting circuit coupling with current extraction and injection structure is added.When the reference output voltage increases with the increase of temperature,the part of positive temperature coefficient current is extracted.when the reference output voltage decreases as the temperature rises,the part of positive temperature coefficient current is injected.The single positive temperature coefficient current is used to correct the high temperature component of the reference output voltage to reduce the temperature drift coefficient.Based on 0.5 μm CMOS process model,the circuit is simulated by using Cadence Spectre software,and the simulation results show that the temperature characteristics have been greatly improved.When the temperature is in the range of-40～+125 ℃ ,the temperature drift coefficient is only 0.5057×10-6/℃,and the PSRR is-81.8 dB at low frequency.The bandgap reference circuit can operate normally at a minimum supply voltage which is approximately2.4V.

Key words: bandgap reference voltage source, curvature compensation, low temperature drift coefficient, current extraction, current injection