The concepts behind the most powerful circuital simulation tool on the market.

1. 1 Copyright Piero Belforte 2013
Piero Belforte 20/02/2013
Leonardo Da Vinci, Leda and the SWAN (1510)

2. 2 Copyright Piero Belforte 2013
Spicy SWAN concepts
The new concept behind Spicy SWAN is that the user can choose
between two FULLY COMPLEMENTARY simulation engines
(Spice,DWS), like it happens for HYBRID ENGINE cars.
SWAN/DWS maps the circuit/system under analysis on an
equivalent DIGITAL WAVE NETWORK, so that no Nodal Analysis
equations solution is required as happens for Spice.
It is enough to apply the samples of voltage/current sources to
this DSP equivalent to get the samples of results (voltages,
currents, powers, waves etc,) in the desired points of the network
WITHOUT SOLVING any equation.
DWN (Digital Wave Network) algorithms are extremely fast,
accurate and stable with respect classical NA and open a BRAND
NEW WORLD of simulation and modeling possibilities to the user.
As known, NA-based simulation engines suffer of poor modeling
capability of signal propagation effects because NA assumes no
signal propagation in the circuit under analysis. This last
assumption is no more valid for dealing with modern high-speed
circuitry when signal transition times are comparable to physical
propagation delays. DWS Trasmission Line model is extremely
fast and accurate, while NA (Spice) TL models are slow and
inaccurate. Time delays are also accurately modeled in most DWS
primitives (like controlled resistors and sources) allowing the
user to model very accurately timing issues.

3. 3 Copyright Piero Belforte 2013
DWN algorithms are fully compliant to NYQUIST criterion of
sampled systems with all the advantages of this feature.
Very simple modeling methods are available in SWAN mode
in addition to classical circuital models, including Behavioral Time
Modeling (BTM), Transmission Line Modeling (TLM), s-plane and
z-plane transfer functions, time-domain S-parameters in addition
to classical circuital models. 2D propagation effects can be also
easily taken into account.
Many circuits/systems out of reach of Spice can be modeled
and simulated with high accuracy and speed.
PWL (PieceWise Linear) behaviors and abrupt time varying
resistors are dealt with no iterations , so that tough situations
like CHAOTIC circuits can be also easily handled.
Time-domain S-parameters blocks don't suffer of the PASSIVITY
and CAUSALITY requirements of Spice, allowing the user to deal
with MULTIGIGABIT-speed circuits /systems in a very simple way
When the comparison is possible, SWAN is more accurate and
faster (typically 50-100X speed up factor) than Spice even when
no propagation effects are taken into account (lumped circuits).
Thanks to DWS calculation speed, lumped/distributed circuits
with hundred thousand elements (RLC,TL,BTM, switches,
controlled sources, pwl non linearities ) can be simulated in
minutes at very low time steps.
Several Million samples (Megasamples or even Gigasamples) are
typically available as outputs of SWAN simulations leading to HD
(High Definition) plots (versus time, XY, Eye diagrams,FFT).

4. 4 Copyright Piero Belforte 2013
Behind SWAN/DWS there has been a research & application
effort of about HALF-MILLENNIUM MAN YEARS spent in a FOUR-
DECADE timeline. Most of real world applications are in the field
of advanced digital systems design, SI (Signal Integrity) , EMC,
FI (Fault Insertion) and are shown in the following links.
Spice still remain a good choice for simulating semiconductor
devices (.model cards) when propagation effects are negligible,
To get more info about SWAN/DWS , I suggest the following
links:
http://www.facebook.com/SpicySchematics
https://docs.google.com/file/d/0BxZqV10CSiNaHlLaFFnUHlFMUE
/edit
https://docs.google.com/file/d/0BxZqV10CSiNX3lDMmtiT0RpZ0E
/edit
Here the link to DWS user manual:
https://docs.google.com/file/d/0BxZqV10CSiNQjAycHFtY1V4OEk/
edit
To try Spicy SWAN for free , it is enough to download the Spicy
SWAN free app on the Ipad or to go to the following link
https://www.ischematics.com/webspicy/portal.py# on the WEB.

5. 5 Copyright Piero Belforte 2013
For more info and applications go to:
https://www.ischematics.com
Fernando Botero, Leda and the Swan