Design And Realization Of A Curvature Compensated Bandgap Voltage Reference Source

A reference source provides higher-precision and opposite reference source in the analog integrated circuits and mixed-signal integrated circuits design. It includes voltage reference source and current reference source. The purpose of its creation reference source builds up a voltage and current that has in dependent of supply voltage, temperature and process, has to make sure temperature coefficient.This designs a very low temperature coefficient bandgap voltage reference wi th curvature compensation. A MOSFET, which is biased in sub-threshold region, is used to compensate the non-line of the VBE, the circuit has very high temperature stability. Make use of current to sue, the output of voltage reference changes in the certain scope with the exportation resistance. For improving the power supply rejection, it adopts the cascade mirror structure.The bandgap reference voltage design reference source in this thesis was fabricated in CSMC0.35μm N-well CMOS process. All the simulation results using Hspice show that the temperature coefficient of the first-order compensated bandgap voltage reference is4.24ppm/℃, while the proposed second-order compensated bandgap voltage reference has0.6ppm/℃low temperature coefficient over the wide temperature range of-55℃～125℃. The output voltage changes from1.6146V to1.6149V in the process corners, the average temperature coefficient of only1.2ppm/℃in simulation and18ppm/℃in testing, meanwhile, power supply current is68μ A and chip area is0.69mm×0.96mm.This designs was fabricated in CSMC. The circuit has rejection of temperature drift and power supply, The measurement results showed that the bandgap voltage reference fulfils the requirements of the program mentioned above. And successful applied for DAC in integrated circuit.