Application Research And Design Of High Performance CMOS Operational Amplifier

From the late twentieth century, revolutionary progress and rapid development were gained in the fields of information and electronic technology. As the representative of digital home appliances, flat-panel televisions, digital television along with DVD are as essential as other industries and electronic technologies in the field of national defense to information technology. As the core of information industry and electronic components, integrated circuits promote the progress and development of these domains of new technologies. With the development of relevant technologies, operational amplifier becomes a very crucial part of the integrated circuit. Consequently, the rapid development of various technologies sets higher requirements to operational amplifier performance.A high-performance CMOS amplifier that uses the basic structure of the two-stage operational amplifier with the supply voltage of ±0.9V is put forward in this thesis. Subsequently, by adding an additional circuit branch, the compensation capacitor and the resistance are separated from the second stage of the operational amplifier. As a result, a dominant pole, a left half plane zero and a non-dominant pole are generated. This enhances the stability of the circuit and leads to a larger unit gain bandwidth and a higher power supply rejection ratio; Based on the design of the two-stage operational amplifier, a band gap reference voltage source is set up, which adopts the structure of Neuteboom voltage source. Curve relation of the output voltage and temperature of the band gap reference source are corrected by the resistance of different temperature coefficient. Then, by using the simulation software Cadence, the relationship between the output voltage and temperature, and the relationship between the output voltage and the supply voltage, as well as the starting time and the power supply rejection ratio are simulated in the TT, FF, SS process corner respectively. After the completion of the pre-simulation, the layout of the operational amplifier and the band gap reference voltage source are drew. At the same time, a post simulation result is obtained after checking the design rules and layout schematic matching.At last, the gain of the operational amplifier reaches 91.39dB, and the power supply rejection ratio reaches 111.8dB. What is more, unity gain bandwidth reaches 26MHz, while power consumption is 68μW. After the curvature correction with the use of band gap voltage reference source, which is designed by the operational amplifier, the temperature drift coefficient gained in the process corner of FF, TT, SS are 4.25ppm/℃,5.69ppm/℃,7.18ppm/℃ respectively. As a result of TT process corner, the output voltage turns out to be 1.17v, and the power supply rejection ratio is 62.92dB, while the start-up time is 50ns. And the design of reference voltage source with a low temperature drift coefficient is realized consequently.