gmoverid-skill
Four skills for analog circuit design: ngspice, gm/ID transistor sizing, the PTM model library and the Sky130A PDK
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Extended access
Why this level
- Scripts run ngspice and Python on the machine and write result files into the working folder.
- For Sky130A the commands install packages and download PDK data.
Install
- Works in
In your terminal, with SkillFoxx CLI
npx skillfoxx add skills/gmoverid-skillDetects the agents on your machine, shows the access level and pins the version.
Other ways to install
Access and checks
How we reviewExtended accessThe tool runs code or makes network calls and only reads external data.
- Scripts run ngspice and Python on the machine and write result files into the working folder.
- For Sky130A the commands install packages and download PDK data.
This is third-party code. Review the repository files before installing.
What it does
The set teaches an agent to design and simulate analog circuits in ngspice. The `ngspice` skill holds nine teaching examples: RC transient, NMOS characteristic curves, filter frequency response, noise, a sample-and-hold switch, a current mirror, a common-source amplifier and transmission-gate on-resistance. The `gmoverid` skill plots transistor characteristics and sizes devices with the gm/ID method. The `GmIdTable` class builds a table from simulation results and, for a given gm/ID and current, finds width, gate voltage, cutoff frequency and the intrinsic gain `gm*ro`. PTM models for 180, 45 and 22 nm are built in. The `transistor-models` skill adds the remaining PTM models: bulk silicon from 180 to 22 nm and FinFET from 20 to 7 nm. The `sky130-pdk` skill explains how to install the open Sky130A PDK through Volare and run process corners and Monte Carlo on a ring oscillator and a five-transistor OTA.
Who it is for. Students and analog circuit engineers who run blocks in SPICE and want an agent to launch simulations and draw plots.
Good fit when
- A transistor must be sized for a given gm/ID and current.
- A SPICE course covers an RC circuit, a filter, a current mirror and noise.
- A ready PTM model is needed for a 32 nm node or 7 nm FinFET.
- The open Sky130A PDK is checked across process corners and Monte Carlo.
Not a fit when
- The project targets a foundry's closed PDK: PTM models serve research and teaching.
- You need board layout or a schematic editor: the set simulates, it does not draw.
- ngspice is not installed and cannot be installed.
Example request
Size an NMOS on the 45 nm HP model at gm/ID of 15 and 100 uA, and show fT and gm*ro.Limitations
A system-wide ngspice install and Python 3 with `numpy`, `matplotlib` and `scipy` are required. For Sky130A `volare` is recommended and downloads the PDK payload when enabled. The PTM models belong to the Arizona State University project: free for research, with citation of the papers listed in the README. The scripts run simulations and write plots and cache into the project working folder rather than the skill folder.
How to disable. Delete the `ngspice`, `gmoverid`, `transistor-models` and `sky130-pdk` folders from `~/.claude/skills` or the project `.claude/skills`. Plots and cache sit in the project working folder.
FAQ
How do I install gmoverid-skill for all projects?
Clone the repository with `--depth 1` and copy `ngspice`, `gmoverid`, `transistor-models` and `sky130-pdk` into `~/.claude/skills`. Check the result with `/skills` in Claude Code.
What is needed besides the skills?
A system ngspice and Python 3 with `numpy`, `matplotlib` and `scipy`. Add `volare` for the Sky130A PDK.
Which technology nodes are built in?
`gmoverid` ships PTM models for 180, 45 and 22 nm. Other nodes, including 32 nm LP and FinFET down to 7 nm, come from the `transistor-models` skill.
What happens on the first `GmIdTable` call?
The first call runs an ngspice simulation and stores the result. Later calls read the data from the cache.
What does the sky130-pdk skill do?
The PDK itself is not bundled. The skill teaches the agent to install Sky130A through Volare and run simulation across process corners and Monte Carlo. Examples include a ring oscillator, a five-transistor OTA and a two-stage Miller amplifier.
Discussion
No questions or reviews yet.
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Comparison with similar tools
Cards that share the main search query, and how they differ.
| Tool | Official | Authentication | Repository stars | Main difference |
|---|---|---|---|---|
| gmoverid-skill (this card) | no | 143 | ||
| eda-agent | no | not required | 324 | edits projects in Altium, KiCad and EasyEDA; gmoverid-skill simulates circuits and sizes transistors in ngspice |
| Verilog Generator | no | 327 | writes digital RTL in Verilog; gmoverid-skill covers analog circuits and SPICE simulation |
README in short
For each node the skill draws three plot sets: IV characteristics, four gm/ID quadrants and gate capacitances. Channel-length and cross-node comparisons are included, for example 180 nm against 22 nm HP.