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.

Felicitas PCBSim 3.0 now comes with a 3D engine which allows to view layouts conveniently in 3D. This greatly helps the layout engineer to improve the routing of critical signals, to solve tricky routings and to optimise layer stacks.

  • Displays all layers and board dimensions.
  • Allows to selectively view individual signals and contacts.
  • Presents the board from any angle (very convenient to look at the rear side).
  • Uses the colours defined in EAGLE.

Including our 3D engine is a strategic move for us. It is the basis for future developments like post-layout simulations and export of 3D data.

The Beta version of Felicitas PCBSim 3.0 will be available from Monday, 22nd February.

Felicitas Customized Engineering is for the 5th time exhibiting at the Nuremberg embedded world 2016 from 23rd to 25th of February. Visit us at booth 4-151. This year we present as highlight version 3.0 of Felicitas PCBSim, our circuit simulator for mixed analog / digital, signal integrity and high frequency simulations.

Felicitas PCBSim is part of the Seminar Advanced PCB Design with EAGLE 7 Circuit simulations with Felicitas PCBSim and rapid PCB prototyping with the Circuit Board Plotter from LPKF

The seminar takes place on Wednesday, 8th of February, 2016 from 9am to 5pm at Martinsried near Munich. 



  • Create hierarchical schematics (modules, ports, components, net classes, buses, ERC, several circuit sheets, BOM)
  • Create layouts (consistency circuit / layout, GND plates, Gerber files)
  • Libraries intensive (pick a component for which you need a library)
  • Circuit simulation
  • Introduction into transmission lines
  • Calculation of signal lines and signal integrity
  • Rapid prototyping with a circuit board plotter incl. presentation

More information and the possibility to sign in can be found here

Version 2.1 is a minor release. It focuses on two main improvements:
On one hand on network and floating licences. These are especially useful for larger companies or universities. On the other hand on the capability to easily do a Fourier analysis on all visible tracks. This allows for example to do a measurement of conductive emissions or to check for cross modulations in HF circuits.

Added or Updated Functionality

  • Added user friendly Fourier Analysis.
  • Added Licence Manager and the capability for floating licences and network licences.
  • Added Update Manager which allows to role out new version automatically.
  • Curves can now be easily selected in diagrams.
  • The background colour of diagrams can now be changed to white.
  • The number format for Bode diagrams can be changed from dB to plain numbers.
  • The IBIS and S-parameter help documentation has been updated.
  • A search field is now available on the right hand side of all help screens. This is searching the whole content of the online help (currently around 250 pages).

Changes to the Simulation Library

  • Added transformer with 3 windings.
  • Added Line Impedance Stabilization Network to measure conductive emissions.
  • Added s-parameter measurements.


  • Changed from EAGLE version 7.3.0 to 7.4.0


  • Setting init conditions now works correctly even if the simulated without determine the dc operation point.
  • Eliminated a syntax error of the Universal Spice Parser for certain B-sources.
  • IBIS file model dialog: The fields io-type, model selector and model are now correctly updated when choosing a model for the first time.
  • IBIS Viewer: The pullup and pulldown curves have sometimes been displayed incorrectly (did not affect simulation). This have been corrected.
  • Virtual oscilloscop: Fixed issues with color of traces made visible with the space bar. Sometimes new traces have not been visible. This is fixed now.