Source: https://guthlabs.ai/docs/instruments/switching-regulator-boost-component-calculator/

instrument / verified-with-binding-errata

# Switching Regulator (Boost) Component Calculator

The current ledger marks this instrument verified with errata that must be applied at binding time.

Status: **VERIFIED_WITH_ERRATA**Lifecycle: **verified-with-binding-errata**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/switching-regulator-boost-component-calculator/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/switching-regulator-boost-component-calculator/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/switching-regulator-boost-component-calculator/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/switching-regulator-boost-component-calculator/qualification/>)

## Ledger state

The current ledger marks this instrument verified with errata that must be applied at binding time.

**Area**: Electrical & Electronics Engineering — Circuits, Power Systems, Electronics Lab

**Tranche**: tranche-5

**Evidence ID**: t5-017

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The specification is not complete enough to verify the claimed Cout and peak-current outputs uniquely. The test vectors use explicit conventional ideal-CCM assumptions. Vector 3 has a corrected capacitor calculation: 0.75×(7/12)/(1000000×0.12)=0.0000036458333333 F.

### Formula and scope findings

- The capacitor-sizing formula for Cout is missing; a common ideal-CCM formula is Cout=Iout*D/(f*ΔVout), assuming specified absolute output-voltage ripple and negligible ESR.

- The switch/diode peak-current formula is not stated. Under ideal CCM boost assumptions, average inductor current is IL_avg=Iout/(1-D), and switch and diode peak current are typically IL_avg+ΔIL/2, but conduction intervals and nonideal losses are not specified.

- D=1−Vin/Vout is the ideal steady-state boost duty-cycle formula only for Vout>Vin and ideal continuous-conduction operation; real designs require voltage-drop and efficiency allowances.

- The input list says ripple targets but does not identify output-voltage ripple ΔVout, which is required to calculate Cout.

### Unit assumptions

- Vin and Vout are in volts, Iout and ΔIL are in amperes, frequency is in hertz, ΔVout is an absolute voltage ripple in volts.

- L is returned in henries and Cout is returned in farads; convert to microhenries or microfarads only for display.

- All test vectors use ideal CCM boost equations, negligible switch and diode voltage drops, negligible capacitor ESR, and steady-state operation.

- ΔIL is the peak-to-peak inductor-current ripple.

- For the stated peak-current outputs, IL_avg=Iout/(1-D), and both switch and diode peak current are taken as IL_avg+ΔIL/2.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

The boundary and zero-denominator inputs require rejection, and the CCM/DCM branch is not defined even though the stated equations are explicitly idealized CCM equations. The capacitor-sizing formula and ripple convention are also omitted or ambiguous in the specification.

## Errata and corrections

### Tranche errata

**Cout_F** · vector 1,3

v1 4.1667e-6, v3 4.375e-6

v1 8.333e-6, v3 3.646e-6 (Iout·D/(f·ΔV), which her own v4 uses exactly)

output-capacitor convention flips between vectors: v1 halves it, v3 uses IL_avg instead of Iout, v4 standard

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "inputs": {
    "Vin_V": 12,
    "Vout_V": 24,
    "Iout_A": 2,
    "freq_Hz": 500000,
    "delta_IL_A": 1.2,
    "delta_Vout_V": 0.24
  },
  "expected_outputs": {
    "D": 0.5,
    "L_H": 0.00001,
    "Cout_F": 0.0000041666666667,
    "IL_avg_A": 4,
    "switch_peak_A": 4.6,
    "diode_peak_A": 4.6
  },
  "working": "D=1−12/24=1−0.5=0.5. L=12×0.5/(500000×1.2)=6/600000=0.00001 H. Cout=2×0.5/(500000×0.24)=1/120000=0.0000083333333333? Correction: denominator 500000×0.24=120000; numerator 1; therefore Cout=0.0000083333333333 F. IL_avg=2/(1−0.5)=2/0.5=4 A. Peak=4+1.2/2=4+0.6=4.6 A for both switch and diode."
}
````

## Related workflows

No source-defined multi-instrument workflow membership is recorded.

## Sources and evidence

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

- `VERIFIED_LEDGER.json · VERIFIED_WITH_ERRATA`

- `evidence-tranche5/tranche5-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`