Full custom design of a two-stage fully differential CMOS amplifier with high unity-gain bandwidth and large dynamic range at output

This paper presents the full custom design of a two-stage fully differential CMOS amplifier with outstanding characteristics of high unity gain bandwidth and large dynamic range at output. Both the theoretical calculations and computer aided simulation analysis are given in detail. The simulation results in CSMC 0.6mum CMOS process from a 5V voltage supply demonstrate that the designed amplifier has satisfied state-of-the-art design specifications with a dedicated optimization technique: the amplifier exhibits a large output swing of nearly plusmn4.75V, a fast settling time of less than 13.4ns to the 0.05% accuracy; while the open loop amplifier has a considerable gain as high as 86.8dB, the differential AC loop unity gain bandwidth reaches 966MHz and the dynamic range at output gets 84.4dB. In this paper, we also present how to efficiently design and further optimize the circuit topology and parameters in order to meet some strict specifications given in advance for a specific engineering project