CALCULATORS / ANALOG CIRCUITS AND FILTERS

Op-amp gain and headroom calculator

Ideal non-inverting op-amp closed-loop gain.

analog-op-amp-gain.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

Scenario	gain	outputV
	11	2.2
	9	1.8

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

output rail budget2.20 V✓ passes

BASELINE INPUTS

feedback10000 ohmground1000 ohminput0.2 V

CALCULATED

gain11

output2.2 V

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Op-amp gain and headroom
# Scope: Ideal non-inverting op-amp closed-loop gain.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

feedback = 10000 ohm
ground = 1000 ohm
input = 0.2 V

gain := 1+feedback/ground
output := input*gain [V]

check output rail budget: output <= 5 V

scenario alternative: feedback = 8000 ohm

Calculated from your source · not saved

Baseline · Baseline

output rail budget2.20 V ✓ passes

alternative · alternative

output rail budget1.80 V ✓ passes

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

gain: gain = 1+feedback/ground
output: output = input*gain [V]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

feedback: 10000 ohm
ground: 1000 ohm
input: 0.2 V

Calculated

gain: 11
output: 2.2 V

Assumptions and limits

Ideal non-inverting op-amp closed-loop gain.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Op-amp gain and headroom. Inputs: topology; resistors; supplies; input/output range. Outputs: closed-loop gain; saturation screening. Model scope: Lumped small-signal models within device operating ranges. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

Inputs: topology, resistors, supplies, input/output range
Outputs: closed-loop gain, saturation screening
Modes: calculate, compare, sweep
Drawing: Schematic and Bode plot

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS