---
title: "Transimpedance Amplifier calculator — AperiOptic"
description: "Feedback resistor for desired output voltage from photodiode current. Free online optics calculator, with the formula and code snippets."
url: "https://aperioptic.com/calculators/transimpedance-amplifier"
---

# Transimpedance Amplifier calculator

Feedback resistor for desired output voltage from photodiode current.

Category: [Detectors](https://aperioptic.com/calculators)

Formula: `Rf = Vout / (R·P)`

## Inputs

| Input | Parameter | Unit | Default |
| --- | --- | --- | --- |
| Optical power | `P` | µW | 1 |
| Responsivity | `R` | A/W | 0.5 |
| Target Vout | `Vout` | V | 2 |

## Result with the default inputs

- Photocurrent: 0.5 µA
- Rf: 4.0000e+6 Ω

Open it with your own values: put each input in the address as a parameter, for example [`/calculators/transimpedance-amplifier?P=1`](https://aperioptic.com/calculators/transimpedance-amplifier?P=1). A unit other than the listed one goes in `<parameter>_unit`.

Read more: [Wikipedia: Transimpedance amplifier](https://en.wikipedia.org/wiki/Transimpedance_amplifier)

[All optics calculators](https://aperioptic.com/calculators)

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The interactive page: https://aperioptic.com/calculators/transimpedance-amplifier (AperiOptic runs in the browser; free, no account). Every page of the site as Markdown: https://aperioptic.com/llms.txt