SPICE Electronics & Analog Circuit Simulation

ModelScript features high-performance native support for SPICE (.cir, .sp, .net, .lib) netlists and analog circuit analysis. Engineers can validate electrical schematics, detect topological faults (floating nodes, voltage source loops), execute pure in-WASM circuit simulations, and export to Modelica or ECAD netlist graphs.

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Capabilities & Supported Formats

Format	Extension	Description
SPICE Netlist	.cir, .sp, .net	Circuit description specifying passive components (R, L, C), active semiconductors (diode, BJT, MOSFET), independent/dependent sources, subcircuits, and simulation directives.
SPICE Model Library	.lib, .mod	Device physics parameters for transistors, diodes, op-amps, and macro-models.

Key Architectural Features

• Engineering Unit Netlist Parser:
  • Robust lexer parsing metric prefixes (f, p, n, u, m, k, meg, g, t), curly brace math expressions {R1 * 2}, line continuations (+), and subcircuit definitions (.SUBCKT / .ENDS).
  • Lossless round-trip serializer (serializeSpice()).
• Native Numerical Solvers:
  • DC Operating Point (.OP): Assembles Modified Nodal Analysis (MNA) matrix $\mathbf{G}\mathbf{v}=\mathbf{i}$ with Newton-Raphson iteration for non-linear PN junctions.
  • Transient Simulation (.TRAN): Numerical companion-circuit integration supporting Trapezoidal rule with damping for reactive elements ($L,C$).
  • AC Small-Signal Frequency Sweep (.AC): Complex admittance matrix $\mathbf{Y}(j\omega )$ solving decade/octave/linear frequency sweeps and bode response.
• Circuit Linter Rules (M7101–M7109):
  • Identifies single-connection floating nodes, parallel ideal voltage sources, cutsets of ideal current sources, non-positive passives, and subcircuit pin mismatches.
• Bilateral Modelica & ECAD Projections:
  • Translates SPICE netlists to standard Modelica.Electrical.Analog components.
  • Projects to generic NetlistGraph data structures for PCB layout, schematic capture, and Design Rule Checking (DRC).

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Command Line Interface (msx spice)

msx spice <action> [files...] [options]

Action	Description	Key Options
simulate	Runs DC operating point, transient, or AC analysis (AC sweep from the .AC card).	--analysis op|tran|ac, --tstep, --tstop, --format table|json|csv, --out
lint	Runs pre-flight structural and electrical rule checks.	--format
inspect	Dumps topology, component breakdown, nodes, models, subcircuits, and directives.	--format, --out
to-modelica	Translates the netlist to Modelica 3.x electrical components and connections.	--out
to-ecad	Projects the netlist to an ECAD netlist graph for PCB routing and DRC.	--out
to-dae	Lowers the netlist directly into the linear-memory DAE arena.	--format, --out
diagram	Renders the circuit schematic to SVG or a JSON graph.	--format, --out
sync	Synchronizes tuned parameters and topology from Modelica back into the netlist.	--from-modelica, --strategy, --out

Examples

# Calculate DC bias voltages on all circuit nodes
msx spice simulate LowPassFilter.cir --analysis op

# Simulate transient step response and export trajectory
msx spice simulate PowerSupply.cir --analysis tran --tstep 1e-6 --tstop 0.01 --out transient.csv

# Run the AC frequency response defined by the netlist's .AC directive
msx spice simulate AudioAmplifier.sp --analysis ac --format csv --out bode.csv

# Lint netlist for floating electrical nodes and ground connectivity
msx spice lint SensorFrontEnd.net

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Electrical Linters & Diagnostic Rules

10 rules9 error1 warning Run with msx lint

Code	Rule	Severity	Message
M7101	spice-floating-node	error	Floating node '<nodeName>' has no DC reference path to ground.
M7102	spice-voltage-loop	error	Voltage source '<vName>' forms a closed loop of ideal voltage sources without series resistance.
M7103	spice-current-cutset	error	Node '<nodeName>' is connected strictly to ideal current sources (current cutset).
M7104	spice-unresolved-subcircuit	error	Subcircuit '<subName>' is referenced by '<compName>' but not defined.
M7105	spice-invalid-passive-value	error	Passive component '<compName>' has invalid non-positive value <val>.
M7106	spice-timestep-violation	error	Transient analysis directive specifies invalid timestep '<tstep>' or stop time '<tstop>'.
M7107	spice-duplicate-device	error	Duplicate component name '<compName>' detected in circuit scope.
M7108	spice-missing-model	error	Active device '<compName>' references undefined model '<modelName>'.
M7109	spice-pin-count-mismatch	error	Subcircuit instance '<compName>' connects <nodeCount> pins but definition '<subName>' expects <portCount> ports.
M7110	spice-malformed-directive	warning	Malformed or unsupported directive '<dirName>'.

Generated from languages/spice/src/lints/rules.ts. All languages →