Feedback System (Part-D)

Today, we're discussing how feedback connections impact the output resistance of voltage amplifiers. Can anyone tell me what happens to output resistance in an ideal situation?

I think it becomes zero because feedback takes over?

Great! In an ideal feedback setup, yes, the output resistance is theoretically zero. Now, if we consider real-world applications, how do finite resistances affect the output resistance?

They would increase the output resistance, right?

Exactly! This concept is crucial for understanding how we can design circuits to maintain desirable output characteristics. Remember, output resistance affects how well the circuit can drive loads, so keep this in mind. Let's move on to derive the output resistance formula.

Now that we know how to calculate output resistance, can anyone explain how feedback changes voltage gain?

Does feedback reduce the gain?

Exactly! A feedback factor, denoted as β, modifies the gain, often reducing it to improve linearity and bandwidth. Knowing how to adjust these factors is essential in circuit design.

So, if β increases, the voltage gain will decrease more?

That's correct! This relationship helps engineers create more stable circuits. Who can summarize the key points we just discussed?

Let's delve into how non-ideal feedback affects circuit performance. What complications can arise with finite input and output resistances?

It could cause signal loss, making the amplifier less effective?

Exactly, signal loss increases as resistances affect current and voltage levels. This is why we often require ideal conditions in theory but must account for real-world elements.

Are there equations to calculate these factors?

Yes! The output resistance expressions can be derived under various conditions, and it helps us understand the limitations of our designs.

Moving on, let's compare trans-impedance and trans-conductance amplifiers. Can someone explain the basic difference between these types?

I think trans-impedance amplifiers convert current to voltage while trans-conductance does the opposite.

Exactly! It's crucial to understand how feedback influences each type's output resistance. Feedback can enhance performance and stability across configurations.

Are the feedback effects similar in both configurations?

Yes, while the signals may differ, the principles of feedback apply similarly. Let's summarize the different configurations and their output effects.

So, why is feedback important in real-world circuits?

It helps stabilize the gain and improve bandwidth?

Exactly! It also reduces distortion and increases linearity. Understanding feedback's role is vital for any electronics engineer!

What kind of feedback do we often apply in practical amplifiers?

Typically, negative feedback is used to achieve stable and predictable performance. Let's conclude our session by reviewing the formulas derived and their applications in circuit design.