analog-sizing-loop

analog-sizing-loop is a skill for Claude Code, Codex from vibeic/vibe-ic. It costs 64 tokens per session (2,795 once invoked), scanned A, original, Apache-2.0.

An automated loop for adjusting transistor sizes in an analog circuit, generating a simulation netlist, running simulations across process, voltage, and temperature conditions, and checking the results against specifications.

In plain words
What is it for?
Use it to optimize an analog block after an initial topology and sizing exist, especially when a SPICE simulation shows failing operating corners on GF180 or SKY130 processes.
Why use it?
It replaces repeated manual resizing and simulation when some operating conditions fail. The loop focuses on the worst failing condition and stops when the required corners pass or the iteration limit is reached.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is python3 programs/loop_admission_guard.py decision.json.

Part of the vibe-ic plugin — 70 skills, 8 commands, 8 agents, 2 hooks, 1 MCP server shipped together

Good fit Use it to optimize an analog block after an initial topology and sizing exist, especially when a SPICE simulation shows failing operating corners on GF180 or SKY130 processes.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/vibeic/vibe-ic
agentmods
npx agentmods add skills/vibeic/vibe-ic/analog-sizing-loop

Made for: Claude Code, Codex.

Or install vibe-ic, the plugin that ships this one along with the rest of its 70 skills, 8 commands, 8 agents, 2 hooks, 1 MCP server.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for analog-sizing-loop

README.md
[![agentmods](https://agentmods.dev/badge/skills/vibeic/vibe-ic/analog-sizing-loop.svg)](https://agentmods.dev/skills/vibeic/vibe-ic/analog-sizing-loop)
Your own site
<a href="https://agentmods.dev/skills/vibeic/vibe-ic/analog-sizing-loop"><img src="https://agentmods.dev/badge/skills/vibeic/vibe-ic/analog-sizing-loop.svg" alt="Measured on agentmods" height="20"></a>
Per session 64 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,795 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00064 $0.02795
Opus 5 $0.00032 $0.01398
Sonnet 5 $0.00013 $0.00559
Haiku 4.5 $0.00006 $0.00280

Measured 8d ago against content hash 03d2331427f7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

analog-sizing-loop scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (tests/test_compliance.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

vibe-ic-marketplace/plugins/vibe-ic/skills/analog-sizing-loop/SKILL.md · 223 lines

How it starts

The opening of the file, as written. The whole thing — 223 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Analog Sizing Loop

Automates the iterative analog design loop that previously required 5-14 manual iterations (per PRACTICAL_NOTES.md). Orchestrates analog-sizinganalog-netlist-geneda_spice_corner in a closed loop with spec-driven convergence.

When to use

  • Step A4 of the analog track (after topology + initial sizing)
  • When a single SPICE run shows failing corners and the user wants automated optimization
  • After /analog-sizing provides an initial design point

Inputs

  1. analog/<block>/spec.json — performance targets with min/max limits
  2. analog/<block>/topology.md — selected topology
  3. analog/<block>/sizing.md — initial sizing from analog-sizing
  4. PDK (gf180 or sky130)

Loop workflow

Iteration 0:
  analog-sizing → initial W/L + bias
  analog-netlist-gen → SPICE deck
  eda_spice_corner (TT only) → quick sanity check
    If TT fails → re-size immediately (don't waste time on corners)

Iteration 1-N (max 5):
  eda_spice_corner (all corners: TT/SS/FF × -40/25/125°C)
  yield-vs-spec + worst-corner   → enforced by programs/corner_yield_vs_spec_check.py
  If all PASS → done
  If FAIL:
    1. (deterministic) worst corner is reported by corner_yield_vs_spec_check.py
    2. (JUDGMENT) identify the DOMINANT failure at that corner — gain shortfall
       vs the spec it violates may live in M1's gm, the load impedance, or the
       bias point; the canned table only approximates this.
    3. (JUDGMENT) identify the SENSITIVE device — which transistor's
       gm/parameter actually drives the failing spec for THIS topology.
    4. once the failure mode is named, the canonical parameter delta is a
       table lookup → enforced by programs/sizing_adjust_policy.py
    5. Re-generate netlist with new sizes; re-simulate
  • TT-only on iteration 0, full PVT sweep on iter ≥1 — enforced by programs/corner_schedule_policy.py (policy emit + sizing_history audit).
  • Yield-table vs spec.json limits + worst-corner argmin — enforced by programs/corner_yield_vs_spec_check.py (re-derives PASS/FAIL from spec.json min/max, independent of any pre-computed status field).
  • Convergence-strategy table (named failure mode → canonical sizing delta) — enforced by programs/sizing_adjust_policy.py:

Read the full file on GitHub · 223 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 223 lines · 64 tokens per session scan A 03d2331427f7

Subscribe to this mod's changes

analog-sizing-loop is a skill published in the GitHub repository vibeic/vibe-ic (23 stars, last pushed today), licensed Apache-2.0. It adds 64 tokens to every session and 2,795 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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