Which factor determines the gain of the voltage series feedback amplif...
Understanding Voltage Series Feedback Amplifier Gain
The gain of a voltage series feedback amplifier is primarily influenced by the ratio of two resistors in the feedback network. Here's a detailed explanation:
Open Loop Voltage Gain
- Open loop voltage gain refers to the gain of the amplifier without any feedback applied. While it sets the initial gain level, it does not directly determine the final gain when feedback is employed.
Feedback Voltage
- Feedback voltage is the voltage returned from the output to the input of the amplifier. Although crucial for stability and linearity, it does not dictate the gain but rather regulates the output based on the feedback network.
Ratio of Two Resistors
- The key factor that determines the gain in a voltage series feedback amplifier is the ratio of two resistors in the feedback circuit. This resistance ratio sets the amount of feedback applied to the amplifier, thus controlling the overall gain.
- For instance, if resistors R1 and R2 are used in a feedback configuration, the gain can be expressed as A = R2/(R1 + R2). This equation shows that the gain is directly influenced by how these resistors are chosen.
Gain of Feedback Circuit
- The gain of the feedback circuit is an important consideration, but it is not the primary determinant of the overall amplifier gain. Instead, it works in conjunction with the resistor ratio to establish the final output.
Conclusion
In summary, while several factors contribute to the performance of a voltage series feedback amplifier, it is the ratio of two resistors that fundamentally determines its gain. Understanding this relationship is essential for designing effective feedback systems in electrical engineering.
Which factor determines the gain of the voltage series feedback amplif...
In setting the gain of the voltage series feedback amplifier, the ratio of two resistors is important and not the absolute value of these resistors. For example: If a gain of 11 is desired, we choose R1 = 1kΩ and R1 = 10kΩ or R1 = 100Ω and RF = 1kΩ.