Research And Design Of A High-Precision,Wide Temperature Range CMOS Reference Voltage

The reference voltage source is one of the most widely used chips in integrated circuits.A/D or D/A conversion systems require a high-precision reference voltage source to provide a reference voltage.And in high-performance IC devices,there are many circuits that need to work in a wider temperature range,which puts higher design requirements on the bandgap reference.This paper studies the design of reference voltage source based on CMOS process with high accuracy and wide temperature range.This article uses curvature compensation technology,chopping technology,and trimming technology to achieve a high-precision bandgap reference.Theoretical analysis and calculation of the curvature compensation point and compensation parameters to compensate for the non-linear temperature change of the bandgap reference voltage;in-depth study of the trimming technique,a two-point 8-bit trimming scheme was proposed to improve the initial bandgap reference voltage Accuracy reduces its temperature coefficient;by designing a chopper circuit,it reduces DC offset and 1/f noise.Using Monte Carlo simulation and op amp mismatch simulation,the effectiveness of the chopper circuit is verified,and the influence of the chopper circuit clock on accuracy is analyzed.Based on Huahong 0.18?m CMOS process,the design,simulation and layout design of the bandgap reference circuit with high precision and wide temperature range are completed.The simulation results show that in the range of power supply voltage 1.5V ? 4V,temperature-40 ? ? 125 ?,the temperature coefficient is less than 4 ppm/? and the output voltage value is 1.132 V under the full process angle.In the group data,the average output voltage is 1.13219 V,the standard deviation is 0.002873,the average quiescent current is only 65?A,and the low-frequency power supply rejection is up to 83 d B.