Signal-to-Noise Ratio / SINAD / ENOB Calculator

Inspectable records

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

t5-199

Ledger rows

1

No ledger note is attached.

Review findings

NEEDS_REVIEW because the exact supported conversion direction and the meaning of an input labeled SNR versus SINAD are ambiguous. The stated SINAD-to-ENOB formula is numerically valid under its documented ADC assumptions, but the instrument claims conversions that are not defined by the specification. The honest label should state that it computes approximate ENOB from SINAD in dB unless the missing SNR, THD, and reverse-conversion formulas are added.

Formula and scope findings

• Only ENOB=(SINAD−1.76)/6.02 is specified, so conversion from SNR, THD, or ENOB back to other metrics is not defined.
• The formula is standard only for SINAD expressed in dB and is an ADC full-scale sine-wave approximation; it is not a universal SNR-to-ENOB formula when distortion is significant.
• No formula is provided for combining SNR and THD into SINAD, or for converting SINAD/THD between amplitude-ratio and power-ratio definitions.
• The claimed bidirectional conversion between SNR, SINAD, THD, and ENOB is therefore incomplete.

Unit assumptions

• SINAD input is in decibels (dB), not a linear ratio.
• ENOB output is reported in bits and is dimensionless mathematically.
• The constants 1.76 and 6.02 assume the conventional ideal ADC quantization-noise model with a full-scale sine-wave input.
• SNR, SINAD, and THD must have explicitly documented reference and ratio conventions before conversions among them are implemented.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The only supplied equation defines SINAD-to-ENOB arithmetic. It does not define SNR-to-SINAD, THD-to-SINAD, or any actual formula branches, and it does not specify validation for units or extreme magnitudes. Large finite JavaScript inputs also lose the 1.76 subtraction through floating-point precision.

Errata and corrections

Tranche errata

Inspectable example

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

{
  "inputs": {
    "SINAD_dB": 1.76
  },
  "expected_outputs": {
    "ENOB_bits": 0
  },
  "working": "ENOB=(SINAD−1.76)/6.02=(1.76−1.76)/6.02=0/6.02=0 bits. Boundary case: SINAD equal to 1.76 dB produces zero ENOB."
}

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