Design of PSRR Enhanced Bandgap Reference Circuit

The high PSRR bandgap reference circuit with high power supply rejection ratio and low temperature drift suitable for low-drop output with low power consumption is described in this paper. Based on the existing traditional bandgap reference circuit,a simple structure of PSRR enhancement circuit is added between the error amplifier and the output end of the bandgap reference current mirror,making the bandgap reference increased by nearly 20 dB than the general structure of the PSRR. Results based on the CSMC 0. 5 μm process Spectre simulation show that the output voltage changes in the value is only 0. 3 mV between the temperature range of -25 ℃ and 85 ℃ , which has good temperature characteristic. When the 10 K power supply rejection ratio is 75 dB at 60 ℃ and the output voltage at the power supply voltage of 2. 75 V ～ 5 V,the fluctuation is only 90 μV. The whole circuit has a good linear adjustment rate. The power consumption of the entire circuit is less than 20 μA.