Bandgap Voltage Reference Source Based On Chopper And Second-order Curvature Compensation Technology

This paper presents a bandgap voltage reference with chopper modulation and second-order curvature compensation technology.Based on 0.55 um CMOS process,the bandgap voltage reference was simulated with Hspice and verified by high and low temperature test chamber.It has temperature coefficient less than 20 ppm/? between-40~125? by using second-order curvature compensation technology.After verification,the bandgap reference module can be applied to power management buck converter as output sampling feedback voltage.This paper first describes the principle of traditional bandgap reference and analyzes its output accuracy decrease caused by op-amp input offset voltage,leads to commonly modulation methods and the chopper modulation technique.Secondly,introduced sub-modules which including bias circuit,starting circuit etc.Then shows traditional first-order temperature compensation principle and how the secondary curvature correction could obtain a low temperature drift and high precision reference voltage.Finally,demonstrates the simulation result and layout placement.By using a HTOL test chamber,DC voltage source and other equipment,to verify chip parameters for the design,check the accuracy from design to verification to complete the entire process.