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What is FrugalEDA?

FrugalEDA is a free, open source, cross-platform user-friendly environment dedicated to energy-frugal electronics based on the amazing quantum properties of superconductors. Its main focus is on superconducting electronics design, including Single-Flux-Quantum (SFQ) digital electronics and variants like Adiabatic Quantum Flux Parametron (AQFP), energy-efficient eSFQ, eRSFQ families, as well as analogue superconducting electronics (SQUIDs, SQIFs,...).

At its centre is JOINUS-D (Josephson Interface Utility Software for Digital Superconducting Circuit Simulations), the main desktop application. It brings the LibrePCB schematic editor, the JSIM and JoSIM simulators, the SuperLibre component library and the embedded FrugalPlot viewer into a single workflow: draw a superconducting circuit, convert it to a SPICE netlist, simulate it, and analyse margins, yield and optimization — all without leaving one application. The netlist conversion at its core, L2SPICE, is also available as a standalone tool.

FrugalEDA integrates a collection of open-source software tools:

  • LibrePCB, a "free, cross-platform, easy-to-use electronic design automation suite to draw schematics and design printed circuit boards – for makers, students and professionals, from beginners to experts."
  • SuperLibre: A comprehensive library of superconducting components, designed to facilitate the creation of schematics for quantum superconducting electronics circuits using LibrePCB.
  • L2SPICE converts LibrePCB schematics into SPICE netlists for the JoSIM and JSIM simulators, and back-annotates edits into the schematic. It is the conversion engine inside JOINUS-D and also runs as a standalone application.
  • JOINUS-D (Josephson Interface Utility Software for Digital Superconducting Circuit Simulations) is the primary software used for designing, simulating, analyzing, and optimizing superconducting circuits, as well as displaying the results. JOINUS-D leverages L2SPICE as its underlying technology to facilitate the conversion of netlists between LibrePCB and SPICE formats.
  • JSIM (Josephson Junction aware SPICE simulator) is an analog circuit simulator specifically designed for superconducting electronics and Josephson-junction-based circuits. It provides SPICE-based transient simulations of superconducting circuits and has been widely used for Single-Flux-Quantum (SFQ) circuit design and analysis.
  • JoSIM (Josephson Simulator) is a modern SPICE-compatible analog circuit simulator specifically designed for superconducting circuits. It supports superconducting elements such as Josephson junctions, implements the RCSJ model, and performs transient simulations while providing simulation results in standard data formats.
  • FrugalPlot serves as an interactive graphical tool that enables users to visualize results on graphs and input digital criteria using the mouse, thereby feeding JOINUS-D algorithms.
  • QtGrace is a 2D Qt-based 2D scientific plotting and data-analysis tool derived from Grace. It allows users to import numerical data, create and edit two-dimensional graphs, perform analyses such as curve fitting and FFT, and export publication-quality plots.
Note

LibrePCB, JSIM, JoSIM, and QtGrace are external tools integrated into FrugalEDA to facilitate and streamline the circuit design workflow.

Key Features

  • Cross-platform compatibility – Works on Windows, macOS, and Linux
  • Dual interface for most of tools – Both GUI and CLI available
  • Multiple simulator support – Compatible with JoSIM and JSIM simulators
  • Subcircuit support – Generate reusable subcircuits
  • Bidirectional netlist conversion – Convert from LibrePCB to SPICE format and back
  • History tracking – Navigate through netlist conversion states
  • Circuit analysis and optimization – Analyse margins, fabrication yields, optimize
  • Integrated dashboard – Easily adjust design parameters and visualize simulation results in real time.
  • Examples - Learn by doing from a set of superconducting circuit examples

Getting Started

  • Install FrugalEDA – Install FrugalEDA in a minute
  • Design your first superconducting digital circuit – Follow the guide at your pace and visualize results
  • Have a look at SuperLibre, the Superconductor library – Learn about the schematic symbols and parameters
  • L2SPICE Quick Guide – Get up and running with LibrePCB-to-SPICE netlist conversion
  • JOINUS-D User Manual – The main application: design, simulate, analyse margins and yield, and optimize
  • Try an example – Open L2SPICE and click “Try an example”. Explore the schematic in LibrePCB and the generated netlist in L2SPICE, then simulate the circuit and analyze the results using the accompanying example note. Take it further with JOINUS-D by calculating circuit margins and yield and performing circuit optimization.
  • Go further – After completing the example, dive deeper into L2SPICE, JOINUS-D, and the other FrugalEDA tools by exploring their user manuals and documentation.

FrugalEDA is open source software. For the latest updates and source code, visit our repository.