Professional Courses
Industry-relevant training in Business, Technology, and Design to help professionals and graduates upskill for real-world careers.
Categories
Interactive Games
Fun, engaging games to boost memory, math fluency, typing speed, and English skillsβperfect for learners of all ages.
Typing
Memory
Math
English Adventures
Knowledge
Interactive Audio Lesson
Listen to a student-teacher conversation explaining the topic in a relatable way.
Introduction to Feedback in Amplifiers
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Welcome, everyone! Today we're discussing feedback in amplifiers. Can anyone tell me what feedback is in the context of electronics?
Isn't feedback when you take some output and feed it back to the input?
Exactly! And it's crucial because it can stabilize gain and reduce distortion. We can categorize feedback as either **negative** or **positive**. Who can explain the difference?
Negative feedback reduces the gain, right? It helps to improve linearity.
Positive feedback increases gain but can lead to instability.
Great! Remember, negative feedback is typically used to improve stability and linearity.
Understanding Trans-Conductance Amplifiers
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Now, let's focus on trans-conductance amplifiers. What defines a trans-conductance amplifier?
I think it's where the output is a current based on input voltage?
Correct! The output current is proportional to the input voltage. This means we have to carefully consider how feedback affects this proportion. What differs in output resistance for trans-conductance amplifiers?
It can change based on the feedback configurations, right?
Exactly! Output resistance changes with feedback, either increasing or decreasing, depending on the configuration, which we need to analyze.
Calculating Output Resistance
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Let's derive some formulas for output resistance in our configurations. Who wants to start with the calculation for the ideal feedback?
In the ideal case, input and output resistances are infinite and zero respectively, showing an infinite output resistance?
Right! But when we introduce finite resistances, how does the equation change?
We use the feedback factors and the voltage relationships to derive the output resistance based on the changes.
Good observation! So, can someone summarize how feedback affects output resistance?
It modifies the output resistance based on the feedback network characteristics, allowing us to design circuits with desired attributes.
Introduction & Overview
Read a summary of the section's main ideas. Choose from Basic, Medium, or Detailed.
Quick Overview
Standard
This section discusses the concept of output resistance in trans-conductance amplifier configurations under ideal and non-ideal feedback conditions. It outlines several feedback network configurations, their impact on output resistance, and how feedback affects overall circuit performance.
Detailed
Detailed Summary
This section delves into the analysis of Trans-Conductance Amplifier Configurations by focusing on how feedback affects output resistance. The output resistance is a crucial parameter in the performance of amplifiers, influencing their bandwidth and linearity. The section covers:
- Feedback Circuit Configuration: The feedback circuits are described as having either voltage or current outputs, and various configurations (shunt, series, etc.) impact the overall behavior.
- Ideal vs. Non-Ideal Scenarios: The ideal conditions assume infinite input resistance and zero output resistance; however, practical scenarios involve finite resistances leading to adjustments in output current and resulting values.
- Output Resistance Calculation: For different feedback configurations, the section explains how to derive the expressions for output resistance taking into account the relationships between input voltage, output current, forward gains, and feedback factors.
- Real-World Applications: The significance of analyzing these configurations is linked to practical applications in designing robust electronic circuits that perform reliably under various operating conditions.
Youtube Videos
Audio Book
Dive deep into the subject with an immersive audiobook experience.
Understanding Trans-Conductance Amplifiers
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
So, here we do have the trans-conductance amplifier here and the forward amplifier it is you can see here the signal it is current and the signal here it is voltage. So, the mixing here it is series and sampling here it is also series. So, this is series connection or current sampling series mixing feedback network.
Detailed Explanation
The trans-conductance amplifier is a type of amplifier that converts an input current into an output voltage. In this configuration, both the sampling and mixing are done in series, meaning the components are arranged in such a way that the output is affected directly by the input current. When we say 'forward amplifier', we refer to the part responsible for amplifying the signal, which in this case introduces a current input and voltage output relationship.
Examples & Analogies
Imagine a water faucet (representing the current input) connected to a water tank (representing the output voltage). When you turn the faucet on (input current), water flows into the tank (output voltage) and fills it up, demonstrating how a small change in the current can significantly affect the amount of water in the tank.
Finding the Output Resistance
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
Here also it will be very similar to our previous discussion as we said that to get the output resistance. So, we need to stimulate this circuit by one voltage source and then we can observe the corresponding current here. Keeping the input port condition it is supporting the feedback network namely we are keeping the source with a source signal of 0.
Detailed Explanation
To determine the output resistance of a trans-conductance amplifier, we apply a voltage to the circuit and measure the resulting current. This method tests how much the output responds to changes in input conditions. Specifically, we maintain a condition where the input source has zero signal so that we can effectively isolate the feedback networkβs behavior without external interference.
Examples & Analogies
Think of a factory assembly line where you add a piece and measure how many products are produced as a result. If you shut off any raw material input (keeping the source signal at zero), you can see how the assembly line performs purely based on existing conditions and configurations without outside influence.
Understanding Ideal Conditions
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
In ideal condition to start with we are considering source term in equivalence equivalent source resistance = 0. So, from that we can say v = β v.
Detailed Explanation
In an ideal scenario, we assume that there is no resistance affecting the input or output, which allows us to analyze the circuit's performance without the complications of real-world resistance values. This simplifies our calculations and helps us understand the theoretical maximum efficiency of the amplifier's operation.
Examples & Analogies
Imagine trying to push a toy car on a perfectly smooth and frictionless surface (ideal condition). The car would move without any impediments. In practical scenarios with a rough surface (resistance), the carβs speed would reduce, just as real amplifiers' output would decrease due to resistive losses.
Calculating Output Resistance Under Non-Ideal Conditions
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
So, let me clear again clear the board and let we continue the discussion. Now, if we consider non-ideal factors namely if I consider this is nonzero, then I have to consider the corresponding Ξ²β².
Detailed Explanation
When we introduce non-ideal conditions, such as finite resistances, these factors directly influence the operational performance of the amplifier. The parameter Ξ²' represents the adjusted feedback factor considering these resistances in the circuit, which directly impacts the output resistance we are measuring.
Examples & Analogies
Think of a sprinter running on a track. Normally, the track is perfect (ideal conditions), allowing fast, unhindered performance. However, if the track has obstacles (non-ideal conditions), the sprinterβs speed is adversely affected, similar to how resistances affect an amplifier's performance.
Definitions & Key Concepts
Learn essential terms and foundational ideas that form the basis of the topic.
Key Concepts
-
Trans-Conductance Amplifier: Converts input voltage to output current.
-
Feedback: A process where part of the output is routed back to the input.
-
Output Resistance: The equivalent resistance seen by the load at the output.
Examples & Real-Life Applications
See how the concepts apply in real-world scenarios to understand their practical implications.
Examples
-
A circuit exhibiting transconductance behavior converts a 1V input to an output current of 1mA, thus demonstrating a transconductance of 1 mS.
-
When negative feedback is applied, the output resistance of an amplifier could theoretically increase, improving overall linearity.
Memory Aids
Use mnemonics, acronyms, or visual cues to help remember key information more easily.
π΅ Rhymes Time
-
In feedback, we trust, for outputs adjust. In amplifiers, they must, to maintain the thrust!
π Fascinating Stories
-
Imagine a ship (the amplifier) sailing with the wind (the input). Too much wind without the anchor (feedback) can cause chaos in the sea (circuit performance).
π§ Other Memory Gems
-
F.O.C.U.S: Feedback Output Conductance Under Stabilization.
π― Super Acronyms
R.E.L.A.Y.
- Resistance Evaluates Linear Amplifier Yield.
Flash Cards
Review key concepts with flashcards.
Glossary of Terms
Review the Definitions for terms.
-
Term: TransConductance Amplifier
Definition:
An amplifier where the output current is a linear function of the input voltage.
-
Term: Output Resistance
Definition:
The resistance seen by the load connected to the output of an amplifier.
-
Term: Feedback
Definition:
The process of feeding back a portion of the output signal to the input.
-
Term: Negative Feedback
Definition:
A feedback loop where the output is fed back in a way that opposes the input signal.
-
Term: Ideal Feedback
Definition:
Theoretical conditions under which the input and output resistances are infinite and zero respectively.