Designing NMOS Amplifiers: Key Parameters and Techniques

This lecture focuses on the design of NMOS amplifiers, emphasizing the use of NMOS transistors as voltage amplifiers. The instructor begins by referencing previous work with bipolar transistors, highlighting the transition to NMOS technology. Key concepts include the biasing of the NMOS gate using resistors, establishing the operating point, and understanding the IV characteristics of NMOS devices. The lecture covers the importance of coupling capacitors for AC signals and the significance of the transconductance parameter (gm) in amplifier design. The instructor explains how to model the NMOS amplifier, considering the output resistance and the impact of frequency on performance. The relationship between gain and gm is discussed, along with the trade-offs involved in achieving high gain versus maintaining a compact design. The lecture concludes with a discussion on the implications of current density and device size on amplifier performance, providing insights into optimizing NMOS amplifier designs for various applications.