Design Of A High Precision BiCOMS Bandgap Voltage Reference

With the development of semiconductor process and circuits design technology, Analog integrated circuit improved greatly in recent years. There is a challenge to the performance of circuits. Also with the popular use of electronic system powered by battery, the request for the functions of the analog Integrated-Circuit is much higher.Bandgap reference voltages are important analog circuit blocks. It can provide a nearly constant reference voltage which is stabilized over process power supply and temperature variation. It makes the bandgap reference voltage be used extensively in Analog to Digital Converter(A/D C). Digital to Analog Converter(D/A C), Power management circuits and memories. At the same time, bandgap reference voltage is simple in structure and more reliable, it could be implemented in standard CMOS process ,so it's suitable for mass production. At present, the bandgap reference voltage has been the most popular reference voltage generator in CMOS integrated circuits.This thesis dose a research on the important voltage reference inside the power management chip which is popular nowadays and design a high accuracy and high power supply rejection ratio(PSRR)bandgap voltage reference which is suit for the step-down chip of DC-DC circuit. UMC 0.6um skill is used for the whole circuit. A cascade current mirror is chosen, a two-stage operation amplifier is added into the power, and the output of two-stage operation amplifier is used for the bias circuit of itself. The appropriate design gets a high PSRR. On the other hand, it takes up a temperature compensation technology to improve temperature stability. HSPICE is used for the simulation for the whole circuit, simulation showed that the output voltage varied lower than 1.5mV with a temperature range of -40℃-80℃and the lower PSRR was higher than 75dB.