关键词: 带隙电压基准源, 电源抑制比, 低功耗 , 温度系数

Abstract: A reference voltage circuit based on feedback circuit is designed. Through the positive and negative feedback, the output reference voltage can obtain a high AC power supply rejection ratio(PSRR), which provides a stable voltage for the follow-up circuit. NPN triode is used to eliminate the influence of op amp offset voltage on the accuracy of bandgap reference voltage, and to compensate the circuit temperature, which greatly reduces the temperature drift. The whole circuit is realized by 0.35 μm CMOS process. The simulation is carried out by spectre simulation software at room temperature of 27 ℃ and working voltage of 4 V. The output voltage of bandgap reference is 1.28 V, the static current is 2 μA, the temperature coefficient is about 18.9×10-6 /℃, and the AC PSRR is about –107 dB in the temperature range of –20-80 ℃. The reference voltage source has the advantages of simple structure, low power consumption and high power rejection ratio.

Key words: bandgap voltage reference, power supply rejection ratio, low power consumption, temperature coefficient