56.6.3. CC followed by CE Configuration

So, in the next slide we will be mixing CE and CC. So, for our reference so, we do have the main table we are keeping it here and we will see that how the CE and CC will be helping us to improve the performance to start with let you consider CC and CCs together and then probably we will see the CE and CC.

So, we do have the basic CC configuration and its main characteristic or main rather from requirement is that input is at the base and output is at the collector. So, if I consider say one transistor we do have see input here feeding at the base of this transistor and let me call this is Q and then it is output it is going to the second transistor.

In this chunk, we introduce the basic configurations we will be discussing: the Common Collector (CC) and Common Emitter (CE). The CC configuration is characterized by having the input connected at the base and the output taken from the collector. The discussion indicates that we are exploring the performance enhancements achieved by configuring these transistors together, specifically the CC followed by CE setup.

Think of the CC configuration like a relay system in a factory where an operator (input) signals a machine (output) to perform a task. The operator sends requests from a control room (base) and receives feedback through the machine's outcomes (collector). Conversely, the CE configuration amplifies the operator's request, making it more impactful, just like sending a strong signal over a weak one.

So, we do have the second transistor here and let you call this is Q and of course, the collector here and collector here should be connected to the main supply, better be connected to main supply. In fact, we can have some resistance also connected there, but for ideal condition we want that and if you see they are bias conditions.

This chunk highlights the importance of correctly connecting the two transistors in our configuration (CC followed by CE). It mentions that the collectors of both transistors must be connected to the main supply for ideal operation. Additionally, the chunk touches on biasing conditions that ensure transistors operate effectively within the circuit.

Imagine two workers in an assembly line who need to communicate effectively for the entire system to function. They are like the transistors in this circuit setup. The 'main supply' is like a central manager overseeing everything, ensuring both workers have what they need (proper connections) to perform their tasks efficiently.

Let me draw this small signal equivalent circuit and if we are feeding the signal directly to the base of the second transistor, then we can draw the small signal model of the first transistor and then followed by the second transistor. Let me use that blue color just for consistency of the other diagram.

Here, we discuss the small signal model which allows us to analyze the circuit's behavior under small variations in input signals. Feeding the input directly to the base of the second transistor is a crucial step in understanding how signals propagate through the two-transistor setup. This will help us to explore the amplification and performance improvement we expect.

When adjusting the volume on a speaker, small increments in the control adjust the sound output. Similarly, this small signal model allows us to observe tiny changes in input signals and understand their effects on the overall system performance, predicting how 'louder' or 'quieter' our output (signal) will be as it passes through the stages.

So, the purpose of CC stage first one is input impedance. So, the advantage rather, we are writing here. So, the advantage here it is the input resistance. So, input resistance is very high very very high. On the other hand, if you see the output resistance and we are looking for this output resistance would be as small as possible.

This section focuses on two critical parameters, input and output resistance. The CC configuration is known for producing a very high input resistance, making it ideal for applications where limited current draw from previous stages is desired. Conversely, a low output resistance is also desirable as it allows for better power transfer to the next stage of the circuit.

Think of input resistance as a very fine filter at the door of a high-end club, allowing only a specific audience to enter without disproportionately stressing the host (previous circuit stage). A low output resistance acts as a smooth exit, allowing patrons to leave freely without complex procedures blocking their way out to keep the flow of traffic (signal) efficient.

Now, let us see the other configuration namely CE and CC. So, mixing across different configuration. So, we do have the CE stage circuit here CE configuration and then also we do have the CC configuration, and let us see how they can be mixed together to get the combined circuit.

In this chunk, we examine the potential of combining the Common Emitter (CE) with the Common Collector (CC) configuration. The aim is to leverage the benefits of both stages, possibly achieving both high gain from the CE stage and high input resistance from the CC stage, thus enhancing overall performance.

Imagine a dynamic relay race team. The first runner (CE stage) is fast but requires careful handling (good input), while the second runner (CC stage) is endurance-focused, providing a steady finish. Combining these different running styles optimally maximizes the team's relay performance, just like hybrid configurations enhance circuit functionality.

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