Example: Calculating Op-Amp Gain
You're designing an audio preamplifier using an op-amp. You want to control the gain by selecting appropriate resistor values.
Case 1: Inverting Mode
In inverting mode, the voltage gain is calculated using:
\[ A_v = -\frac{R_f}{R_{in}} \]
Suppose you choose:
- Input resistor: \( R_{in} = 1\;k\Omega \)
- Feedback resistor: \( R_f = 10\;k\Omega \)
Then the voltage gain is:
\[ A_v = -\frac{10\;k\Omega}{1\;k\Omega} = -10 \]
This means the output will be inverted and amplified by a factor of 10.
Case 2: Non-Inverting Mode
In non-inverting mode, the gain is given by:
\[ A_v = 1 + \frac{R_f}{R_{in}} \]
Using the same resistor values:
- Input resistor: \( R_{in} = 1\;k\Omega \)
- Feedback resistor: \( R_f = 10\;k\Omega \)
Then:
\[ A_v = 1 + \frac{10\;k\Omega}{1\;k\Omega} = 1 + 10 = 11 \]
The output will be non-inverted and amplified by a factor of 11.
Use the Calculator
Enter the resistor values and select the mode in the calculator:
- Input resistor: 1 kΩ
- Feedback resistor: 10 kΩ
- Mode: Inverting or Non-Inverting
The calculator will compute the correct gain based on the configuration.
Disclaimer: These calculators are provided for informational purposes only. Always verify your designs against relevant engineering standards and consult a qualified professional. We do not take responsibility for any errors or damages resulting from the use of these calculations.