Performance Evaluation of Analog Circuits with Deep Submicrometer MOSFETs in the Subthreshold Regime of Operation

In addition to its attractiveness for ultra-low power applications, analog circuits based on the subthreshold operation of the devices can have significantly higher gain as compared to their superthreshold counterparts. In this paper, we systematically study the analog performances in terms of g_m, g_m/I_d etc of conventional deep submicrometer MOSFETs in the subthreshold region. We also predict such performances with the help of an improved drift-diffusion based current model. The circuit performances (gain, output current etc) are also studied and a very good agreement between the simulation results and the corresponding model prediction is obtained