Non-Inverting Amplifier
Vout = Vin × (1 + Rf/Ri)
Quick answer
This calculator solves Vout = Vin × (1 + Rf / Ri) for Output Voltage. With Input Voltage 26.4 V, Feedback Resistor 10 kΩ, Input Resistor 22 kΩ, the result is 38.4 V. It solves in 4 directions, so you can enter the values you have and get the one you need.
Calculator
Formula
Description
The non-inverting op-amp configuration applies the input signal to the positive input terminal and uses a resistor divider between the output and the inverting input for negative feedback. The gain is always greater than or equal to unity, set by the ratio of feedback to input resistor plus one. This topology provides high input impedance because the signal connects directly to the op-amp non-inverting input. It is widely used for buffering sensor signals, amplifying differential signals, and in active filter stages.
Variables
- Vout — Output voltage (V)
- Vin — Input voltage (V)
- Rf — Feedback resistor (Ω)
- Ri — Input resistor from inverting input to ground (Ω)
Practical Notes
When Rf = 0 and Ri is open (removed), the gain is unity and the circuit becomes a voltage follower (buffer). The output cannot exceed the supply rails (or slightly less for non-rail-to-rail op-amps). Gain-bandwidth product limits the usable gain at high frequencies.
Symbols and units
| Symbol | Meaning | Default unit | Accepted units |
|---|---|---|---|
| Vout | Output Voltage | V | pV, nV, µV, mV, V, kV |
| Vin | Input Voltage | V | pV, nV, µV, mV, V, kV |
| Rf | Feedback Resistor | kΩ | mΩ, Ω, kΩ, MΩ |
| Ri | Input Resistor | kΩ | mΩ, Ω, kΩ, MΩ |
Step by step
- 1. What you know: Input Voltage 26.4 V, Feedback Resistor 10 kΩ, Input Resistor 22 kΩ
- 2. The relation: Vout = Vin × (1 + Rf / Ri)
- 3. Substitute: Vin = 26.4 V, Rf = 10 kΩ, Ri = 22 kΩ
- 4. Result: Output Voltage = 38.4 V
Related quantities from the same inputs
- P = V² / R = 69.7 mW
- I = V / R = 2.64 mA
Worked examples
Minimum range
Given: Input Voltage 0.726 V, Feedback Resistor 100 Ω, Input Resistor 0.22 kΩ
Result: Output Voltage = 1.056 V
Low range
Given: Input Voltage 7.26 V, Feedback Resistor 1 kΩ, Input Resistor 2.2 kΩ
Result: Output Voltage = 10.56 V
Typical
Given: Input Voltage 26.4 V, Feedback Resistor 10 kΩ, Input Resistor 22 kΩ
Result: Output Voltage = 38.4 V
High range
Given: Input Voltage 0.506 kV, Feedback Resistor 100 kΩ, Input Resistor 0.22 MΩ
Result: Output Voltage = 0.736 kV
Maximum range
Given: Input Voltage 5.06 kV, Feedback Resistor 1 MΩ, Input Resistor 2.2 MΩ
Result: Output Voltage = 7.36 kV
Solving for each variable
Solve for Output Voltage
Input Voltage 0.726 V, Feedback Resistor 100 Ω, Input Resistor 0.22 kΩ → 1.056 V
Solve for Input Voltage
Output Voltage 0.33 V, Feedback Resistor 100 Ω, Input Resistor 0.22 kΩ → 0.2269 V
Solve for Feedback Resistor
Output Voltage 0.33 V, Input Voltage 0.726 V, Input Resistor 0.22 kΩ → -120 Ω
Solve for Input Resistor
Output Voltage 0.33 V, Input Voltage 0.726 V, Feedback Resistor 100 Ω → -0.1833 kΩ
How Output Voltage changes with Input Voltage
| Input Voltage (input) | Output Voltage (result) |
|---|---|
| 5.81 V | 8.451 V |
| 14.53 V | 21.13 V |
| 29.05 V | 42.25 V |
| 43.58 V | 63.38 V |
| 58.1 V | 84.51 V |
| 87.15 V | 126.8 V |
| 116.2 V | 0.169 kV |
| 0.2324 kV | 0.338 kV |
| 0.4067 kV | 0.5916 kV |
| 0.581 kV | 0.8451 kV |
The same result in other units
| Unit | Value |
|---|---|
| mV | 38400 |
| V | 38.4 |
| kV | 0.0384 |
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<p><a href="https://vbatpower.com/formulas/opamp-noninvert/">Non-Inverting Amplifier</a> Calculator by vbatpower.com</p>Frequently asked questions
How do you calculate Non-Inverting Amplifier?
Use Vout = Vin × (1 + Rf / Ri). With Input Voltage 26.4 V, Feedback Resistor 10 kΩ, Input Resistor 22 kΩ, Output Voltage works out to 38.4 V.
What is the formula for Non-Inverting Amplifier?
The formula is Vout = Vin × (1 + Rf / Ri). The non-inverting op-amp configuration applies the input signal to the positive input terminal and uses a resistor divider between the output and the inverting input for negative feedback.
How do you find Input Voltage when you know the other values?
Rearrange for Input Voltage: with Output Voltage 0.33 V, Feedback Resistor 100 Ω, Input Resistor 0.22 kΩ, Input Voltage is 0.2269 V.
How do you find Feedback Resistor when you know the other values?
Rearrange for Feedback Resistor: with Output Voltage 0.33 V, Input Voltage 0.726 V, Input Resistor 0.22 kΩ, Feedback Resistor is -120 Ω.
What units does Non-Inverting Amplifier use?
Output Voltage is shown in mV, V, kV. Values are held in SI base units internally, so you can mix prefixes without converting by hand.
Related Concepts
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