SLiCAP — more than symbolic SPICE
Analog design is complex.
Systems engineering tells us how engineers solve complex problems.
SLiCAP makes it doable.
A simulator tells you what your circuit does — after you have chosen the components. SLiCAP tells you what the components must be: it turns a circuit into symbolic design equations, so values follow from your requirements instead of from guessing and re-simulating.
Since version 5.2 it comes with the Structured Electronic Design Environment, which integrates SLiCAP and NGspice into one workspace. It keeps every design decision traceable — from the specification, through the budgets, to the final design report — so you can design first-time-right.
pip install slicap # then start the environment with: slicap
From specification to design report, in one chain
- Specification. Functions, performance and cost requirements are written down as project data — the reference every later decision is checked against, not a note in the margin.
- Budgeting. SLiCAP expresses performance and cost as explicit functions of your device properties — you allocate each contribution its share of the requirement, and solving the expression gives the value that property must have. Noise, DC variance, tolerance, matching and temperature drift all budget the same way.
- Design and verification, one environment. Create and solve design equations with simple, solvable models, and verify your design with NGspice's full device models.
- Report generation. Create graphs, LaTeX and RST snippets from expressions, tables and NGspice simulations. Put them in your LaTeX design documents and Sphinx websites, and keep them up to date with one run.
Nothing is locked in: the environment writes a plain Python script you can read, edit, run from the command line, or import from your own design code — and SLiCAP works perfectly well without the GUI.
SLiCAP is the tool set behind the open-access book Structured Electronic Design and the analog electronics courses at Delft University of Technology.
What it looks like
What it can do
Symbolic and numeric analysis of linear, continuous-time circuits: transfer functions and their polynomial coefficients, poles and zeros, root-locus plots and Routh arrays, noise and noise integration, DC variance for tolerance, matching and temperature budgets, inverse Laplace and network solutions.
Feedback circuits are analysed with the asymptotic-gain model — loop gain, asymptotic gain, servo function and direct transfer, each available on its own. Balanced circuits are converted into their common-mode and differential-mode equivalent circuits, so each mode is designed for what it must do.
Out of all of it come the design equations for bandwidth, frequency response, noise, dc variance and temperature stability. Hierarchical netlists, parameter stepping, and NGspice for numeric verification.
→ Full documentation, tutorials and examples: slicap.org
About
SLiCAP is an open-source Python program by Anton J.M. Montagne, created for and used in structured analog design practice, teaching and research.
Two companions to install. NGspice is the
verification half of the environment — install it and your design is simulated with full
device models from inside the same project. A TeX distribution (pdflatex + dvisvgm)
typesets the expressions on your schematics and builds your LaTeX design reports;
without it SLiCAP falls back to plain text — readable, but not what you want in a
document. Sphinx comes with SLiCAP, so design documentation as a website needs nothing
extra.
See slicap.org for installation details and for building from source.
Contributing
Ideas and contributions are welcome — email us. Found a bug? Please report it on the Issues page.
1 maintainer
Release files for SLiCAP 5.2.1
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| slicap-5.2.1.tar.gz | 13.8 MB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| slicap-5.2.1-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 27.9 MB
Release files / slicap-5.2.1.tar.gz
| Download URL | slicap-5.2.1.tar.gz |
|---|---|
| Size | 13.8 MB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
4725711837035864bddccdf11821001b3bd2b4b397deb13f62b65aae929179ef
|
|
BLAKE2b-256 checksum How to use checksums |
dd7934d78be7b64034f88591114f74179d985ba2827f0e921f6d92cc6f219bf6
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.14
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Aug 20, 2026.
Transparency logRelease files / slicap-5.2.1-py3-none-any.whl
| Download URL | slicap-5.2.1-py3-none-any.whl |
|---|---|
| Size | 14.2 MB |
| Tags | Python 3 |
|
SHA-256 checksum How to use checksums |
407448f5923faa2abdd43bcfb6f75df47961896fff2e1619877167e56b816425
|
|
BLAKE2b-256 checksum How to use checksums |
2182d30fdafcc2c05259f15673c52027f80f5da3c4330eb4d0ea2a734e81461e
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.14
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Aug 20, 2026.
Transparency log
