Skip to content

README.md

Latest commit

 

History

History
168 lines (131 loc) · 6.5 KB

README.md

File metadata and controls

168 lines (131 loc) · 6.5 KB
Raw

SpiceSharpParser.CustomComponents

NuGet License: MIT

SpiceSharpParser.CustomComponents is the optional companion package for SpiceSharpParser. It adds LTspice-compatible components and reusable functional subcircuits while keeping the resulting circuit compatible with the normal SpiceSharp simulation API.

The package targets .NET Standard 2.0 and .NET 8.0.

Installation

dotnet add package SpiceSharpParser.CustomComponents

The package depends on SpiceSharp-Parser, so a separate parser package reference is not required.

Enable Custom Netlist Components

The original parser/reader flow keeps parsing, translation, and simulation as explicit steps. Enable the custom mappings on SpiceSharpReader before calling Read:

using System.IO;
using System.Linq;
using SpiceSharpParser;
using SpiceSharpParser.CustomComponents;

string netlistText = File.ReadAllText("circuit.cir");
var compatibility = CompatibilityOptions.LTspice;

// Parse the SPICE text.
var parser = new SpiceNetlistParser();
parser.Settings.Compatibility = compatibility;
var parsed = parser.ParseNetlist(netlistText);

// Translate the parsed model into SpiceSharp objects.
var reader = new SpiceSharpReader();
reader.Settings.Compatibility = compatibility;
reader.Settings.UseCustomComponents();
var model = reader.Read(parsed.FinalModel);

// Run the analysis defined by .OP, .TRAN, .AC, or .DC in the netlist.
var simulation = model.Simulations.Single();
simulation.Execute(model.Circuit);

UseCustomComponents() adds custom-aware mappings for A, C, D, and L elements. Call it before Read, and use the same compatibility settings for the parser and reader. Ordinary diode, capacitor, and inductor syntax continues to use the standard SpiceSharp implementations.

Included Components

Family Supported forms
LTspice A-devices SRFLOP, DFLOP, PHASEDET, COUNTER, SAMPLEHOLD, OTA, VARISTOR, and MODULATOR/MODULATE
Ideal diodes LTspice-style .MODEL D(...) parameters such as Ron, Roff, Vfwd, reverse clamp, smoothing, and current limits
Nonlinear capacitors Charge-defined capacitors using Q=<expression>
Nonlinear inductors Flux-defined inductors using Flux=<expression>
Digital subcircuits Gates, Schmitt inputs, tri-state drivers, multiplexers, an adder, decoder, comparator, open-drain output, latches, flip-flops, a counter, phase detector, and functional 555 timer
Analog subcircuits Sample-and-hold, operational transconductance amplifier, voltage-controlled varistor, and frequency/amplitude modulator

A-device Quick Reference

Every native LTspice A-device has eight terminal positions followed by its model name.

A<name> n1 n2 n3 n4 n5 n6 n7 n8 <model> [parameter=value ...]
Model What it does
SRFLOP Stores one bit using asynchronous set and reset inputs
DFLOP Captures a data bit on a clock edge
PHASEDET Produces signed current pulses from input-edge timing error
COUNTER Counts clock edges and generates a repeating output sequence
SAMPLEHOLD Samples an analog voltage and holds the captured value
OTA Converts differential input voltages into a limited output current
VARISTOR Provides a bidirectional voltage-controlled clamp; like a programmable surge-protection varistor
MODULATOR Generates an amplitude-controlled waveform whose frequency moves between Space and Mark

Terminal 8 is the common node. A terminal position is unused when it repeats that common node. If common is not ground, a literal 0 is an active connection to global ground, not an unused terminal. Unused outputs are electrically detached; an unused MODULATOR amplitude input selects the native amplitude of 1.

Example:

* Divide a clock by four
VCLOCK clock 0 PULSE(0 5 5n 100p 100p 2n 10n)
VRESET reset 0 0

ACOUNT clock reset 0 0 0 qb q 0 COUNTER Cycles=4 Duty=0.5
RQ q 0 10k
RQB qb 0 10k

.tran 100p 42n 0 100p UIC
.save V(clock) V(q) V(qb)
.plot tran V(clock) V(q) V(qb)
.meas tran q_at_30n FIND V(q) AT=30n
.print tran V(q)
.end

Programmatic Subcircuit Use

The embedded libraries can also add components directly to a SpiceSharp Circuit:

using SpiceSharp;
using SpiceSharp.Components;
using SpiceSharpParser.CustomComponents.Digital;

var circuit = new Circuit(
    new VoltageSource("VDD", "vdd", "0", 5.0),
    new VoltageSource("VA", "a", "0", 5.0),
    new VoltageSource("VB", "b", "0", 5.0),
    new Resistor("RLOAD", "y", "0", 10_000.0));

var digital = DigitalSubcircuitLibrary.LoadBuiltIn();
digital.AddBinaryGate(
    circuit,
    DigitalGateKind.Nand2,
    instanceName: "XU1",
    firstInputNode: "a",
    secondInputNode: "b",
    outputNode: "y",
    positiveSupplyNode: "vdd",
    negativeSupplyNode: "0");

Use AnalogSubcircuitLibrary.LoadBuiltIn() for the four analog functional models.

Compatibility Notes

  • A-device support is experimental and intentionally limited to the eight documented families.
  • MODULATOR requires both Mark and Space; COUNTER requires Cycles.
  • SAMPLEHOLD Td is rejected because its native delayed timing semantics are not implemented.
  • Sweep-dependent A-device parameters are rejected instead of being silently frozen at one value.
  • The digital and analog libraries are functional macromodels, not transistor-level replicas of a specific physical part.

Documentation and Examples

License

MIT. See the repository license.