The Design Of CMOS Low Noise Wide Band-width Fully Differential Operational Amplifier

Opamps are widely used in many fields nowadays such as A/D and D/A converter active filter and AGC. All kinds of differential opamps appear for special application.One basic cell of mobile terminal which is fully differential opamp is designed in the thesis. The input stage of fully differential opamp is telescopic circuit and the output stage is common source amplifier For getting proper DC operation point,a common feedBack circuit based on negative feedBack theory is designed For the purpose of wider bandwidth, miler capacitance and miler resistance are used to compensate the poles and zeros .Bypass deducing the noise parameter ,we optimize the noise performance. Simultaneously ,the thesis deduce key point of the circuit such as bandwidth ,phase margin, input equivalent noise ,common input range ,output swing, common rejection ratio ,power supply rejection ratio, slewing rate ,setting time ,power dissipation ,DC gain, and so on ,also we compared it with folded input stage on these performance in details. And then give comprehensive optimization design skills about fully differential OPAMP. In addition, the thesis design test bench about all the parameter desired by the specification in details based on the .definition.The OPAMP is implemented with 0.18um CMOS technology, The pre-simulation and post-simulation are finished by cadence IC5141.The result of post-simulation of fully differential OPAMP is the power dissipation lower than 2.6mw,input equivalent noise less than 6nV/ HZ ,unit bandwidth wider than 145MHz,total harmonic less than -100dB,DC gain higher than 72dB,CMRR larger than 90dB,PSRR lager than 81dB ,output swing bigger than 3.2V,input offset less than 1.5mV,slewing rate lager than 95V/us,setting time smaller than 20ns and so on. All the result above are under the worst condition bypass the PVT simulation...