87.2. Introduction

So dear students welcome back after the break. So, before the break we are talking about the numerical examples of the current mirror.

This chunk welcomes the students back from a break and recalls that previous discussions involved numerical examples related to current mirrors. This indicates continuity in the lecture, prompting students to connect their prior knowledge with what will be discussed next. It sets the stage for applying theoretical concepts to practical examples.

Imagine being part of a play, where each act builds on what happened before. Just like an actor remembers their lines and cues, students need to remember the concepts learned earlier to fully understand the new material being presented.

As you can see here, and there we have used Beta-helper to improve the non-ideality factor coming due to the base current loss namely, this base current loss.

This chunk introduces the idea of non-ideality factors affecting current mirrors, specifically pointing out the influence of base current losses. The use of a 'Beta-helper' suggests strategies or components that can be integrated into the circuit to mitigate these losses. Understanding this is crucial for students as it relates directly to the efficiency and performance of electronic circuits.

Think of a leaky bucket that can't hold water properly. The base current loss represents the water leaking out. A 'Beta-helper' is akin to sealing the leaks to ensure that the bucket retains as much water (current) as possible, providing a better experience (efficiency) in the end.

So in the next example, what we will see that improvisation of the numeric current mirror circuit to take care of the non-ideality factor due to early voltage.

This chunk outlines that the upcoming example will focus on improving the numeric current mirror circuit to address non-ideality caused by early voltage effects. Again, this emphasizes a proactive and adaptive approach to circuit design, which is essential for optimizing performance in real-world applications.

Consider a sports team that keeps losing due to specific weaknesses in defense. The coach (in this case, the instructor) aims to address these weaknesses through targeted training (the next example) to improve overall performance.

To be more precise, we like to place one cascode transistor here and that improves the output resistance of the current mirror.

In this chunk, the introduction of a cascode transistor is described, which serves to enhance the output resistance of the current mirror. The significance of output resistance in amplifying or managing current flows is key for students to grasp as it directly affects circuit stability and performance.

Imagine reinforcing a bridge with additional support beams. Just as this added support helps the bridge hold more weight and remain stable, the cascode transistor strengthens the circuit's ability to manage currents effectively.

So in the next example, we are starting with MOSFET version and then after that we will go to the BJT version.

This chunk indicates that the lecture will transition from discussing the MOSFET version of the current mirror to the BJT version. This transition is essential as it illustrates how different technologies can achieve similar objectives while having their unique advantages and operational nuances.

It's like learning how to draw with pencil first, then moving to charcoal. Both produce art, but each medium requires different techniques and understanding to master.

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