Abstract— There is no doubt that the short-channel effects have affected the analysis and design of modern analog CMOS integrated circuits significantly. Thus, models that take into account these effects must be adopted in order to obtain more accurate results. In this paper, the AC small-signal low-frequency equivalent circuit of the short-channel MOSFET transistor is developed using an appropriate model. The impact of short-channel effects on the operation of basic building blocks of analog integrated circuits such as basic amplifier configurations, cascode stage, differential amplifier and composite transistor is investigated quantitatively. Additionally, the nonlinear distortion is investigated using the adopted model.