The Research And Design Of High Precision Bandgap Reference Voltage Source

In recent years,with the continuous upgrading of electronic products,the performance of chips are required constantly improving.Bandgap reference voltage source is responsible for providing high-precision reference voltage for the system.Its performance directly affects the performance of the whole system.Therefore,the design technology of bandgap reference voltage source is a key technology in analog integrated circuits,and has been a research hotspot.This thesis presents a complete design of a high precision,low temperature coefficient and wide temperature coefficient bandgap voltage reference based on Huahong HHNEC GE0.35 um process.The bandgap voltage reference requires a low temperature coefficient of 2 ppm/?,an output current capacity of-100?A to 15 mA,and a free-load capacitor capacity of 0.1?F to 100?F,which static current is lower than 60?A,and the initial accuracy of ±0.04%,in the temperature range of-40 ? to 125?.At present,there are a lot of research and design about bandgap reference source at home and abroad.The main design difficulties are as follows,the existing technology generally has large process errors,which will directly affect the performance of bandgap reference source,so we must use trimming technology;in order to achieve a lower temperature coefficient,we must compensate the bandgap with high-order temperature,while the existing high-order temperature compensation methods generally sensitivity to process error.In this paper,a special temperature compensation scheme is presented,and a fuse trimming circuit is designed to realize this compensation method,which effectively reduces the temperature coefficient of the bandgap reference source.By choosing the amplifier,driver and frequency compensation method reasonably,the problem of stability under free load capacitance was solved;aiming at the problem of low power consumption,the method of reading the fuse state by power-on reset signal is given,and the related circuit is designed to reduce the power consumption of the trimming circuit part;in order to reduce the additional cost of trimming work,the method of determining the trimming parameters at a single temperature point after the actual tape of the bandgap reference source is studied,and an effective solution is given.The whole system is simulated by Hspice software,and the overall simulation results are given.The simulation results show that the temperature coefficient of bandgap reference voltage source is less than 1 ppm/? in the temperature range from-40? to 125?,and the temperature coefficient is more than 1 ppm/? and less than 2 ppm/? in individual process angle conditions.The current absorption capacity of 100 ?A and the current output capacity of 15 mA can be guaranteed.And the system can remain stable under the free-load capacitance of 0.1?F to 100?F.The PSRR of the system power supply is greater than-100 dB under different supply voltages.And the static current of the system is below 65?A.