A High PSRR Bandgap Reference Circuit with Low Temperature Coefficient
The power supply rejection ratio of the bandgap reference circuit is improved by two ways.Firstly,the peak current source struc-ture is used to introduce the gain of the transistor itself into the feedback loop,thereby improving the loop gain and the power supply rejec-tion ratio of the bandgap reference core.Secondly,the pre-regulator is used to further improve the power supply rejection ratio.Besides,a curvature compensation circuit only requiring a source degeneration asymmetric current mirror is also proposed,which has cross-process versatility.The circuit proposed is verified using a 0.18 μm BCD process and applied to a buck DC-DC convertor.The results show that the proposed circuit has high power supply rejection ratios of 127 dB,134 dB,and 136 dB at 2.4 V,3.3 V,and 5.0 V power supplies respectively,and achieves a low temperature coefficient of 3.74×10-6/℃,with a total current consumption of only 6.3 μA-14.5 μA.
high PSRRcurvature compensationpeaking current sourcepre-regulator
万方数据
维普
