Research And Design Of Low Temperature Coefficient CMOS Integrated Bandgap Reference Voltage Source

The bandgap reference voltage source as a basic module in the circuit,which is widely used in digital and analog circuits.The traditional typical bandgap reference has a poor output temperature coefficient,typically above 100 ppm/?.The requirement of bandgap reference voltage source for high-precision A/D or D/A conversion circuits,high-precision portable devices,and system-on-a-chip(SOC)circuits is increasing day by day.Traditional typical bandgap reference voltage sources are increasingly unable to meet people's needs.It is particularly urgent to research and develop a low temperature coefficient CMOS integrated bandgap reference voltage source.Based on the bandgap source-based design theory and non-ideal characteristics,A new design scheme of temperature compensation based on second-order curvature and NMOS piecewise linear compensation is proposed,which achieves the purpose of effectively reducing the temperature coefficient of the low temperature coefficient CMOS integrated bandgap reference voltage source.In addition,a highly supply voltage rejection ratio of the bandgap reference is achieved by introducing a negative feedback between the power supply and the operational amplifier.SMIC's 0.18?m CMOS integrated circuit process is adopted to complete the circuit design of the low temperature coefficient CMOS integrated bandgap reference voltage source.Then the CMOS circuit simulation verification is completed by the cadence SPECTRE simulation tool.Finally,on the basis of CMOS circuit,the low temperature coefficient CMOS bandgap reference voltage source layout is designed and validated.The main contents of this topic are as follows:1)Theoretical basis,Common temperature compensation method and principle of bandgap Reference Voltage Source;2)Non-ideal characteristics of bandgap is reference source;3)The design of first-order CMOS integrated bandgap voltage reference circuit is completed.On this basis,the temperature compensation circuit which combines second-order curvature and NMOS piecewise linearity is designed;4)The CMOS integrated bandgap reference voltage source circuit simulation and the layout design verification are completed by the CADENCE SPECTRE simulation tool.According to the simulation analysis of CADENCE SPECTRE,the temperature coefficient of CMOS circuit output is 8.8ppm/? in the range of-50~120? at 5V,and the power supply voltage rejection ratio is-80 dB at 27?.When the power supply voltage is 2.8V in the range of 5V,the output voltage regulation rate of the CMOS circuit is 2.3mV/V.In summary,the bandgap reference voltage source studied and designed in this paper has good performance,which can meet the requirements of high-precision portable devices and system-on-chip(SOC)and other circuits.