Source: https://guthlabs.ai/docs/instruments/op-amp-gain-calculator-inverting-non-inverting-diff/implementation/

instrument implementation / implementation-contract

# Op-Amp Gain Calculator (Inverting/Non-inverting/Diff) implementation

A source-bound implementation contract for Op-Amp Gain Calculator (Inverting/Non-inverting/Diff); deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t4-234

**Effect**: Computation or source lookup only

## Input and validation requirements

A zero-valued Rin produces division by zero and an undefined gain/output; the instrument must reject that input rather than emit a numeric result.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "topology": "inverting",
    "Rf": 100000,
    "Rf_unit": "ohm",
    "Rin": 10000,
    "Rin_unit": "ohm",
    "Vin": 0,
    "Vin_unit": "V"
  },
  "expected_outputs": {
    "gain": -10,
    "Vout": 0,
    "impedance_notes": "Ideal model: source input impedance is approximately Rin = 10000 ohm; output impedance is 0 ohm."
  },
  "working": "Av = -Rf/Rin = -100000/10000 = -10. Vout = Av*Vin = (-10)*0 V = 0 V."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/op-amp-gain-calculator-inverting-non-inverting-diff/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/op-amp-gain-calculator-inverting-non-inverting-diff/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/op-amp-gain-calculator-inverting-non-inverting-diff/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche4/tranche4-results.json`