44.2.1. Course Overview

Analog Electronic Circuits Prof. Pradip Mandal Department of Electronics and Electrical Communication Engineering Indian Institute of Technology, Kharagpur Lecture – 44 Common Collector and Common Drain Amplifiers So, dear students welcome back to our NPTEL online certification course. The course title it is Analog Electronic Circuit, and now myself Pradip Mandal from E and EC Department of IIT, Kharagpur. Today’s topic of discussion it is Common Collector and Common Drain Amplifiers. Based on our overall flow let us see where we stand.

In this introduction, Professor Pradip Mandal welcomes students back to the NPTEL online certification course on Analog Electronic Circuits. He sets the context for the lecture by summarizing the course title and the topic at hand, which is focused on amplifiers, specifically the Common Collector and Common Drain configurations. This establishes both the speaker’s credentials and the course structure, essential for understanding the subsequent content.

Think of a guided tour where the guide introduces themselves and outlines the route ahead. Just as a tour guide lays the groundwork for the journey ahead, the professor introduces the topic to prepare students for what they will learn.

We are in week-5 and we are discussing about the building blocks, specifically we are going to discuss as I said common collector amplifier and common drain amplifiers. We will discuss about the basic operation and biasing, and then also we will be discussing about circuit analysis to find its performance parameter expressions. Design part will be covering later, so in the next week probably next discussion will be covering that.

In this segment, the professor outlines the week’s focus on building blocks of Analog Electronic Circuits, particularly highlighting that they will be examining Common Collector and Common Drain amplifiers. The key areas of discussion include their basic operations, biasing techniques, and circuit analysis to derive performance parameters like voltage gain and impedance. It's stated that design elements will be introduced in the following week, indicating a progressive learning approach.

Imagine you're learning how to cook. The instructor explains that this week you'll focus on basics like chopping and boiling before moving on to full recipes. This helps you grasp foundational cooking techniques before tackling more complex dishes.

So, the concepts we are going to cover in today’s discussion it is the following. We shall start with the motivation of going for this new configuration namely common collector and common drain amplifiers, and then basic operation biasing, and then analysis for specifically for voltage gain, input and output impedance of those amplifiers and then input capacitances.

The professor lists the specific topics of today's lecture, starting with the motivation for using Common Collector and Common Drain configurations. Following that, students will learn about their basic operation, biasing methods, and how to analyze these amplifiers, focusing on essential performance metrics, including voltage gain, input and output impedance, and input capacitances. This overview helps students mentally prepare for the intricate details that will follow.

Consider how a teacher outlines a lesson plan: the objectives and key points are like a roadmap, helping students anticipate what they'll cover and enabling them to focus their attention on each segment as it comes.

So, let us see what the basic motivation is, rather let we try to recapitulate whatever the discussion we had in the previous class. Namely, what are the limitations it was there for common emitter and common source amplifier specifically when we are cascading say two stages by connecting output of the one CE amplifier to the input of the next CE amplifier.

In this chunk, the professor discusses the motivation behind exploring new amplifier configurations by reviewing the limitations faced with Common Emitter (CE) and Common Source (CS) amplifiers when cascading them. These limitations relate to how the input and output resistances of the stages can interact and negatively affect the overall signal performance. Understanding these constraints establishes a foundation for why new amplifier configurations, like the Common Collector and Common Drain, are necessary.

Imagine stacking two bookshelves too close together—in trying to fit them, the space limitation causes issues with accessing the books. The professor illustrates how similar problems arise in electronics when combining two amplification stages without considering their interaction.

--