48.2.2. Next Steps: Common Base and Common Gate Configuration

With here it is the analysis the knowledge of the circuit analysis can be utilized where in the analysis part; we have started the calculation from top to bottom of this list.

The analysis of circuit design begins with utilizing foundational knowledge of circuit behavior. This involves a structured approach where calculations are performed from top to bottom on a given list of parameters. This means starting with broad requirements and progressively narrowing down to specific values needed for successful circuit design.

Think of planning a trip. You first determine your overall destination (the top of your list), then you map out the route (the analysis part) and finally decide on the places you will stop along the way (the specific calculations).

Now, if we have to make a design, where in fact, these parameters it will be given to us. Voltage gain should be close to 1, then output impedance it will be given to us.

In designing circuits like common drain or common collector configurations, specific parameters such as voltage gain and output impedance are typically predefined. The objective is to ensure that the output impedance calculated meets these predefined requirements, which is crucial for the circuit's performance.

It's similar to cooking a recipe where the ingredients and measurements are specified. You need to adhere closely to these to ensure the dish turns out perfect.

So, the way we will be preceding while we have to design the circuit it is basically from bottom to up.

The design process often flows in a reverse order; starting from the output impedance which gives a rough idea of the necessary parameters. Once output impedance is established, the transconductance (g) is calculated, which indicates how effectively an input signal can control the output.

Imagine building a puzzle where you start with corner pieces (the output impedance) that frame the puzzle, and then fill in the middle pieces (transconductance) that complete the picture.

And better, we should avoid this resistance and ideally we want this resistance should be 0.

In circuit design, it's preferable to minimize unwanted components such as resistance that do not contribute beneficially to circuit functionality. In ideal conditions, designers aim for zero additional resistance to simplify the circuit and enhance performance, thus avoiding complications that could arise from too many components.

Consider organizing a workspace. The more clutter there is (unwanted resistance), the harder it becomes to find necessary tools. An organized, simplified space (zero resistance) allows for greater efficiency.

So, the summary of the design guidelines is that we start from output resistance particularly for common drain circuit then we calculate g.

The design guidelines emphasize the need to start with the output resistance. From there onwards, transconductance and collector currents are calculated sequentially to ensure proper functionality of the circuit. This methodical approach ensures all electrical parameters fit together effectively.

It's like following a recipe step-by-step; if you skip a step (like calculating the transconductance), the final dish (the circuit) may not turn out as expected.

So, similar kind of guidelines it can be followed for the common collector circuit also.

The design approach outlined for the common drain circuit applies similarly to the common collector circuit. This includes calculating output load conditions based on specific frequency requirements. The process involves adjustments based on collector current and other known device parameters.

If the common drain circuit is a blueprint for a house, the common collector circuit is a blueprint for an apartment; while they differ in layout, both follow the same fundamental construction rules.

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