powertree

Plain-text PCB power tree description (KDL v2), with validation, a steady-state DC solver, per-chip heat, design-rule checks, scenarios, and Graphviz output. Pure Python 3.10+, no runtime dependencies.

pip install -e .                     # or: python -m powertree ...
powertree check  examples/sensor-board.kdl          # findings only; exit 1 on errors (--strict: warnings too)
powertree report examples/sensor-board.kdl -s peak  # nets, functions, chip heat, totals, findings
powertree report examples/rack/rack.kdl --summary   # functions except consumers; board, group, power tables
powertree report design.kdl --load-lines            # plus each consumer's load lines (also on dot)
powertree report examples/rack/io-card.kdl -s peak+low-line   # one board on its own; a+b composes scenarios
powertree report examples/ups.kdl --json            # machine-readable
powertree dot    examples/ups.kdl -s on-battery -o ups.svg   # needs Graphviz for svg/png/pdf
powertree dot    examples/ups.kdl -o ups.png --dpi 300       # raster resolution (default 200)
powertree dot    examples/rack/rack.kdl -s mostly-idle -o rack.svg                     # repeated instances stacked
powertree dot    examples/rack/rack.kdl -s mostly-idle --collapse-boards -o rack.svg   # boards as boxes
powertree dot    examples/rack/rack.kdl --expand IO:3 -o rack.svg   # or --no-stack
powertree dot    examples/ups.kdl --wrap 3 -o ups.svg              # fold long chains into rows of 3
powertree check  examples/rack/rack.kdl --lib corp=examples/lib   # boards, counts, library roots
powertree schema                                    # every node/property, generated from the validator

• SPEC.md — the format reference and solver semantics
• examples/
  • sensor-board.kdl — 12V → 5V → LDO/buck, part library
  • ups.kdl — adapter + battery, OR-ing, charger, harness, waiver
  • rack/ — project file with a library root, a PSU feeding 4 counted io-card boards, board scenarios
• tests/ — pytest (115 tests, including a parity check against the ckdl reference parser when it is installed)

Code layout

Module	Layer
kdl.py	KDL v2 parser with line/column positions
schema.py	declarative structure spec + validator (layer 2)
loader.py	use files, part merge, counts, board flattening, reference resolution (layer 3)
libs.py, paths.py	library roots and stamps; hierarchical paths and selectors
topology.py	ERC-style graph rules, topological order (layer 4)
scenario.py	scenario inheritance
solver.py	DC solve and electrical checks (layer 5)
units.py, expr.py	quantities and the safe efficiency-expression language
analysis.py, report.py, cli.py	pipeline runner, waivers, text/JSON output
graph.py, render.py	Graphviz DOT with instance stacking; rendering via dot

Graphviz

Image output (-o file.svg|png|pdf, or -T to override the extension) uses Graphviz dot. It is found in this order:

1. --dot PATH
2. $POWERTREE_DOT
3. PATH

On Windows the Graphviz installer may not add itself to PATH; set POWERTREE_DOT to e.g. C:\Program Files\Graphviz\bin\dot.exe in that case.

Install it with winget install graphviz, brew install graphviz, or sudo apt install graphviz. Without it, -o file.dot still works.