Source: https://guthlabs.ai/docs/instruments/op-amp-summing-integrator-differentiator-designer/implementation/

instrument implementation / implementation-contract

# Op-Amp Summing/Integrator/Differentiator Designer implementation

A source-bound implementation contract for Op-Amp Summing/Integrator/Differentiator Designer; 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**: t4-246

**Effect**: Computation or source lookup only

## Input and validation requirements

A zero input resistance produces an undefined division and should be rejected. The specification also leaves signed-voltage versus magnitude conventions unstated, allowing a polarity error in the computed output.

## 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": {
    "mode": "summing",
    "Rf_ohm": 100000,
    "V1_V": 0.25,
    "R1_ohm": 25000,
    "V2_V": -0.1,
    "R2_ohm": 50000
  },
  "expected_outputs": {
    "Vout_V": -0.8
  },
  "working": "V1/R1 = 0.25/25000 = 0.00001 A = 10 microA. V2/R2 = -0.1/50000 = -0.000002 A = -2 microA. Sum = 10 microA - 2 microA = 8 microA. Vout = -Rf times sum = -100000 ohm times 0.000008 A = -0.8 V."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/op-amp-summing-integrator-differentiator-designer/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/op-amp-summing-integrator-differentiator-designer/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/op-amp-summing-integrator-differentiator-designer/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`