67.3. Conclusion and Future Work

In summary of this modification what we like to say here it is. In this case by making the connection of this R to the output node, we are making the operating point easily achievable. And then to avoid it is adverse effect on the gain namely the reduction of the gain we are putting this extra capacitor which is making the base node of transistor to ground and hence the corresponding gain it is remaining high.

This part summarizes the modification made to the circuit design. By connecting resistor R to the output node, the operating point of the circuit becomes easier to establish. The presence of an additional capacitor helps to prevent the gain from reducing, ensuring that the circuit maintains its performance. The connection to the ground through the capacitor effectively stabilizes the voltage at the base of the transistor, which is fundamental for ensuring high gain in the output.

Think of this circuit like a team of chefs in a kitchen preparing a meal. If everyone is well-coordinated (the components are properly connected), they can prepare a delicious dish (high gain) efficiently. But if one chef (the resistor) is out of sync and affecting others, the dish may not turn out well. By introducing an assistant chef (the capacitor) who ensures that instructions are clear and consistent, the team can operate smoothly without losing quality in their cooking.

Similar kind of practical circuit can be obtained for common source amplifier also. This is what it is shown here. I will not be going in detail, but just to say that we do have say one resistor here. We do have another resistor here to define the gate voltage of transistor-1 and likewise we do have two more resistors here to define the gate voltage of transistor-2. And then we have to ensure that these two I and I they should be equal and both of the transistors should be in saturation region.

This chunk talks about applying similar design principles to a common source amplifier. Similar to the modifications discussed previously, you need to organize resistors in a way that properly defines the gate voltage for two different transistors. By ensuring the currents are equal and both transistors are operating in saturation, the design maintains efficiency and performance. This reflects the universal approach to circuit design where certain principles are applicable across different configurations.

Imagine a relay race where two runners must pass the baton at the right moment to maintain speed and avoid dropping it (the resistors defining the gate voltages). If they don't coordinate their pace and timing (currents being equal), the overall performance (amplification) of the relay team (the amplifier) suffers. Thus, careful positioning and coordination lead to a faster race time.

Now, to avoid the fine tuning and all or rather to get this condition easily achievable instead of connecting this to ground we can connect this to output node. But then again we must be aware that the moment we connect this resistor to the output node it may feed the signal back here and that may reduce the gain of the circuit because that reduces the output resistance. To take care of that you can put here AC grounding capacitor making the signal coming back here it is bypassed and making the active part of this device equals to 0.

This chunk highlights the importance of using bypass capacitors. Connecting resistors to the output node instead of ground can help achieve design goals but risks feeding back signals that can reduce circuit gain. By incorporating a bypass capacitor, these unwanted signals are effectively eliminated from affecting the circuit, ensuring it remains stable and efficient.

Imagine a concert where a microphone picks up sounds from the crowd in addition to the singer's voice. This can cause feedback that disrupts the performance. Using a sound dampening device (the bypass capacitor) helps to filter out the crowd noise, ensuring that only the singer's pitch is amplified clearly, thus providing a better auditory experience.

And then we have done the analysis to get the expression of voltage gain. And then output resistance for considering the idealistic bias condition. And then we have discussed about practical amplifier circuit where the operating point is possible and achievable with active load.

This section provides a recap of the analysis performed regarding voltage gain expressions and output resistance under ideal bias conditions. The discussion emphasizes the design of practical amplifier circuits that enable the operating point to be effectively established using active loads, showcasing how theoretical models translate into real-world circuits.

Think of this recap as reviewing the key points of a project before presenting them. Just like how a presenter revisits important metrics and findings (voltage gain and output resistance) to ensure clarity for their audience, in electronic design, these principles guide engineers in finalizing circuits that function effectively.

And then we have seen the consequences or at least we have highlighted the consequences. Namely the gain may get affected by those practical circuits having feedback. And then we considered bypass capacitor there to avoid the adverse effect on the gain. And the other two things we yet to cover it as on this topic is that numerical examples may be little bit on the guidelines, but that will be covered in the next class.

This portion discusses future considerations stemming from the circuit's behavior under feedback conditions. It emphasizes the consequences on gain and the need for further exploration of numerical examples, which will enhance understanding of the concepts and guide practical applications in future classes, indicating that the learning journey continues.

Much like a student who finishes a chapter but knows there will be a quiz on numerical problems later, this section prepares the audience for upcoming challenges in understanding circuit behavior amid feedback. Like mastering new math problems builds a solid foundation in mathematical concepts, focusing on these numerical examples will solidify their understanding of electronic principles.

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