What’s New in Version 3.1


FSpice, the simulator core, has been considerably enhanced. Many simulations now run much faster. This is especially true for
large or difficult circuits with fast transients.

FSpice’s capability to simulate very challenging circuits with delicate convergence has also been largely improved.

EAGLE’s hierarchical designs are now fully supported and extremely helpful for larger designs.
Each module can have its own stimulus to develop and test the module before it is used in a larger design.

Version 3.1 further expands the 3D capabilities by adding the feature to view and to export a board completely in 3D.
This includes the components on the board and therefore makes it easy to mechanically integrate an EAGLE design into
any system.

And last but not least: We have started to add comprehensive libraries which contain schematic symbols, footprints, 3D models and simulation models.
The first large set of libraries is already included in this version 3.1.0.

Added or Updated Functionality

  • Schematics can now be parametrised. A special simulation device
    PARAM allows to set parameters. These can be used to
    define the values of passive devices, voltage sources or integrated circuits.
  • It is now possible to measure
    a wide variety of properties from the simulation results. For this a new tab “Measure” has been added to the simulation properties
    dialog of all components.
    Measured properties can for example be rms voltage, average current, frequency, time delay, average power consumption and so on.
    Each measurement result can be automatically checked if it violates predefined thresholds.
  • The support for simulating hierarchical designs has been improved: The hierarchy can now be arbitrary deep. Components can be marked to be simulated only when
    simulating the single module in which they are defined. In this way, each module can have its own stimulus for testing and can still be integrated in a larger design.
  • FSpice convergence and speed has been enhanced. Especially in conjunction with power measurement, digital circuits or XSpice
    device (all devices having a first letter ‘A’).
  • There is a new convergence option “Auto stepping”. With this, the simulation step size is automatically adjusted to how
    quickly the circuit state changes. The option both speeds up simulation and enhances accuracy.
    See Convergence Settings for more details.

  • The Convergence Info tab now contains internal information of FSpice about the simulation process.
    For the experienced user this allows to tune a simulation for speed and convergence.
  • Yet another tab “Device Instances” contains now a flat list of all FSpice device instances. The list can be filtered and sorted.
    This is especially helpful for searching components with high currents. In an ASIC development the components with large currents into substrate can be filtered
    this way.
  • All dc voltages of a circuit can now be ramped up together. This helps to find a dc operation point with difficult circuits.
    See Simulation Settings for more details.
  • Voltage sources configured for pulse output now have an integrated filter,
    which slightly smooths the waveform. This improves speed and convergence.
  • The 3D Module can now show and export the board and the
    components on it in addition to the layout.
  • The Library Editor is now able to handle 3D models as well.
  • It is now possible to change administrative data of multiple models.
  • The simulation model of the Junction Diode has been comprehensively updated. It now accepts almost all
    syntax flavours and extensions in use.

LTSpice (&reg Linear Technology) Compatibility Layer

  • Non-linear capacitor defined by its charge (Q=…), see FSpice Capacitors

Changes to Libraries

A large number of libraries with hundreds of 3d shapes have been added. Apart from this, complete sets of libraries with 3d shapes, EAGLE symbols and
simulation models have been created. The most important being:

Libraries for all the operational amplifiers from Analog Devices:

  • opa-analog_devices.lbr for EAGLE symbols and footprints
  • opa-analog_devices.fic for the simulation models.
  • opa-analog_devices.f3d for the 3D models

Libraries for all the operational amplifiers from Analog Devices:

  • fet-epc.lbr for EAGLE symbols and footprints
  • fet-epc.fmos for the simulation models.
  • fet-epc.f3d for the 3D models

Libraries for all the GaN FETs from GaN Systems:

  • fet-gan.lbr for EAGLE symbols and footprints
  • fet-gan.fmos for the simulation models.
  • fet-gan.f3d for the 3D models

Libraries for SMD power inductors from Coilcraft:

  • inductor-smd-coilcraft.lbr for EAGLE symbols, footprints and simulation parameters.
  • inductor-smd-coilcraft.f3d for the 3D models
  • Added transformers with 4 and 5 windings to Felicitas_SpecialFunctions.fic.
  • Added L_Q, an inductor with losses defined by its Q to Felicitas_SpecialFunctions.fic.


  • Changed from EAGLE version 7.5.0 to 8.4.1.


  • Windows: Under certain conditions PCBSim stopped working after 99 simulations. This is fixed now.
  • Attribute values have sometimes not been treated correctly, if they contain spaces. This is rectified.
  • Mostly on slower computers PCBSim did sometimes not react to the context menu request from EAGLE. This is corrected.

Help Updates

  • The parameter min and max for Non-linear Dependent Sources
    are now documented.