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Fluxus-S

Analytic engine

RSFQ cell characterization

A single-cell datasheet: functional verdict, bias and Ic margins, propagation delay, maximum toggle rate, process-variation yield, and whether the fast surrogate agrees.

For: RSFQ designers characterizing a cell variant before committing it to a library.

1

call for a full single-cell datasheet

margins · timing · fmax · yield

Status. Analytic transient engine, not a surrogate. Gate criteria defined; no measured figure published.

Engine. Analytic transient engine — not a surrogate, and preferred where the answer matters more than latency.

Reference. JoSIM. The quality gate requires per-junction slip counts to match JoSIM exactly and bias / Ic margin bands to agree within one sweep step, on jtl, splitter and the comparator DFF.

API

Endpoints

POST/v1/fluxus/spice/characterize

one cell → datasheet

Base URL https://api.cogitan.ai, bearer key from an approved account. Read GET /v1/fluxus/capabilities first: it states the same fidelity, validation, envelope and refusal conditions as this page. Access model.

Inputs

What you send

cell
a name from the public cell registry
params
knob overrides; GET /v1/fluxus/sfq/schema for names and ranges
ic_sigma_pct
% — per-junction Ic spread for yield
l_sigma_pct
% — per-inductor spread for yield
n_trials
≤ 120 — yield trials

Outputs

What comes back

margins
functional verdict, bias and Ic margins
timing
propagation delay, maximum toggle rate
yield
process-variation yield
surrogate_agrees
fast-surrogate cross-check

Validation

Measured against what, and how

Reference. JoSIM. The quality gate requires per-junction slip counts to match JoSIM exactly and bias / Ic margin bands to agree within one sweep step, on jtl, splitter and the comparator DFF.

Split. Not applicable — an analytic engine, not a learned model.

Measured agreement with JoSIM

not quoted

the pass/fail criteria are defined and the gate is runnable, but its results are not persisted, so no figure is published. No number here means no number was recorded — not that the error is zero.

Speed

What it costs per call

One datasheet

~1–2 min

CPU-bound battery; use the margin surrogate for sweeps

Envelope

Where the answer is trusted

cells
the public cell registry — GET /v1/fluxus/sfq/schema

Refusals

When you get no number

  • Unknown cell or knob: HTTP 400 with a structured error.
  • A section the engine cannot serve quickly returns an unsupported payload instead of failing the whole datasheet.

Known limits

What it does not do

  • Same literature-reconstructed cell library as the margin surrogate; nothing is fab-calibrated.

Every figure on this page compares against a simulator or a published device measurement. None of it is a prediction of your fabricated hardware. For one certification-grade answer, run the full reference; this is for screening many designs cheaply and spending solver time on the survivors.