Design Of Integrated Bandgap Reference

Bandgap reference is one of the most important cells in analog integrated circuits.It outputs a high-precision voltage reference for other functional modules like biascircuit,reference circuit in the system,or a high-precision current reference.The outputof bandgap reference is stable; it is independent of supply voltage, temperature andprocess. Due to the ratio of performance and price,CMOS has become the dominantprocess in integrated circuit design. The thesis mainly contain of designing a highprecision bandgap reference based on CMOS process.The thesis outlines the development history and trends of the bandgap reference,also it analyzes the theory of bandgap reference. By using Cadence,three classicbandgap reference of different architecture have been designed and analyzed. To reachthe goal of high precision and innovation, a piecewise-linear curvatre-correctedbandgap reference based on0.5μm CMOS process has been designed independently.The novel designed piecewise-linear curvatre-corrected bandgap reference standsout for its concise architecture and excellent performance.Two NMOS were used toleak current so as to compensate the nonlinear effect of temperature.By introducingnegative feedback between op-amp and power supply,the Power supply rejection ratioof bandgap reference is improved. This bandgap reference was stimulated in CadenceSpectre,and the results shows a temperature coefficient of8.2ppm/°C in thetemperature range from-40oC to120oC,and the PSRR is83dB,the power supply adjustrate of this bandgap reference is1.05mV/V.