<s>
NgspiceNGSPICE	O
:	O
recent	O
progresses	O
and	O
future	O
plans	O
,	O
P	O
.	O
Nenzi	O
e.a.	O
,	O
MOS-AK	O
,	O
Bucharest	O
2014	O
,	O
http://www.mos-ak.org/bucharest/The	O
NGSPICE	B-Algorithm
circuit	B-Language
simulator	I-Language
,	O
P	O
.	O
Nenzi	O
e.a.	O
,	O
FOSDEM	O
,	O
Brussels	O
2015	O
,	O
https://archive.fosdem.org/2015/schedule/event/ngspice/ngspice	O
,	O
current	O
status	O
and	O
future	O
developments	O
,	O
H	O
.	O
Vogt	O
,	O
FOSDEM	O
,	O
Brussels	O
2019	O
,	O
https://fosdem.org/2019/schedule/event/ngspice/	O
is	O
an	O
open-source	B-Application
mixed-level/mixed	O
-signal	O
electronic	B-Language
circuit	I-Language
simulator	I-Language
.	O
</s>
<s>
It	O
is	O
a	O
successor	O
of	O
the	O
latest	O
stable	O
release	O
of	O
Berkeley	O
SPICE	B-Protocol
,	O
version	O
3f.5	O
,	O
which	O
was	O
released	O
in	O
1993	O
.	O
</s>
<s>
A	O
small	O
group	O
of	O
maintainers	O
and	O
the	O
user	O
community	O
contribute	O
to	O
the	O
ngspice	B-Algorithm
project	O
by	O
providing	O
new	O
features	O
,	O
enhancements	O
and	O
bug	O
fixes	O
.	O
</s>
<s>
Ngspice	B-Algorithm
is	O
based	O
on	O
three	O
open-source	B-Application
free-software	B-Application
packages	O
:	O
Spice3f5	O
,	O
Xspice	B-Algorithm
and	O
Cider1b1	O
:	O
</s>
<s>
SPICE	B-Protocol
is	O
the	O
origin	O
of	O
all	O
electronic	O
circuit	B-Language
simulators	I-Language
,	O
its	O
successors	O
are	O
widely	O
used	O
in	O
the	O
electronics	O
community	O
.	O
</s>
<s>
Xspice	B-Algorithm
is	O
an	O
extension	O
to	O
Spice3	B-Algorithm
that	O
provides	O
additional	O
C	B-Language
language	I-Language
code	O
models	O
to	O
support	O
analog	O
behavioral	O
modeling	O
and	O
co-simulation	O
of	O
digital	O
components	O
through	O
a	O
fast	O
event-driven	O
algorithm	O
.	O
</s>
<s>
Cider	O
adds	O
a	O
numerical	O
device	O
simulator	O
to	O
ngspice	B-Algorithm
.	O
</s>
<s>
Critical	O
devices	O
can	O
be	O
described	O
with	O
their	O
technology	O
parameters	O
(	O
numerical	O
models	O
)	O
,	O
all	O
others	O
may	O
use	O
the	O
original	O
ngspice	B-Algorithm
compact	O
models	O
.	O
</s>
<s>
Ngspice	B-Algorithm
implements	O
three	O
classes	O
of	O
analysis	O
:	O
</s>
<s>
Ngspice	B-Algorithm
implements	O
various	O
circuits	O
elements	O
,	O
like	O
resistors	O
,	O
capacitors	O
,	O
inductors	O
(	O
single	O
or	O
mutual	O
)	O
,	O
transmission	O
lines	O
and	O
a	O
growing	O
number	O
of	O
semiconductor	O
devices	O
like	O
diodes	O
,	O
bipolar	O
transistors	O
,	O
MOSFETs	B-Architecture
(	O
both	O
bulk	O
and	O
SOI	O
)	O
,	O
MESFETs	O
,	O
JFETs	O
and	O
HFETs	B-Algorithm
.	O
</s>
<s>
Behavioral	O
modeling	O
:	O
Internal	O
B-	O
,	O
E-	O
,	O
and	O
G-sources	O
,	O
as	O
well	O
as	O
R	O
,	O
C	B-Language
and	O
L	O
devices	O
,	O
offer	O
modeling	O
by	O
mathematical	O
expressions	O
,	O
driven	O
by	O
node	O
voltages	O
,	O
branch	O
currents	O
,	O
parameters	O
and	O
constants	O
.	O
</s>
<s>
The	O
Xspice	B-Algorithm
codemodel	O
interface	O
:	O
This	O
is	O
a	O
C-code	O
interface	O
that	O
helps	O
the	O
modeling	O
process	O
by	O
simplifying	O
the	O
access	O
to	O
simulator	O
's	O
internal	O
structure	O
.	O
</s>
<s>
C	B-Language
language	I-Language
coded	O
models	O
with	O
spice	B-Protocol
format	O
:	O
As	O
an	O
open-source	B-Application
project	O
,	O
Ngspice	B-Algorithm
allows	O
new	O
models	O
to	O
be	O
linked	O
to	O
the	O
sources	O
and	O
compiled	O
.	O
</s>
<s>
Ngspice	B-Algorithm
supports	O
parametric	O
netlists	O
(	O
i.e.	O
</s>
<s>
Ngspice	B-Algorithm
provides	O
an	O
internal	O
scripting	O
language	O
to	O
facilitate	O
complex	O
simulation	O
and	O
evaluation	O
control	O
flows	O
.	O
</s>
<s>
For	O
mixed	O
signal	O
circuit	B-Language
simulation	I-Language
ngspice	B-Algorithm
allows	O
users	O
to	O
create	O
a	O
user-defined	O
node	O
definition	O
file	O
(	O
UDN	O
)	O
of	O
a	O
new	O
device	O
model	O
interface	O
.	O
</s>
<s>
The	O
implementation	O
of	O
the	O
node	O
is	O
created	O
and	O
simulated	O
by	O
using	O
C	B-Language
language	I-Language
with	O
macros	O
which	O
is	O
compiled	O
by	O
standard	O
C/C	O
++	O
compilers	O
.	O
</s>
<s>
Ngspice	B-Algorithm
may	O
be	O
compiled	O
into	O
a	O
( *	O
.dll	O
or	O
*	O
.so	O
)	O
readily	O
to	O
be	O
integrated	O
into	O
a	O
calling	O
program	O
.	O
</s>
<s>
,	O
another	O
shared	O
library	O
version	O
,	O
offers	O
an	O
interface	O
to	O
Tcl/Tk	B-Application
(	O
software	O
)	O
for	O
better	O
integration	O
with	O
software	O
like	O
XCircuits	B-Application
.	O
</s>
<s>
Ngspice	B-Algorithm
is	O
licensed	O
under	O
the	O
BSD-3-Clause	B-Operating_System
license	O
.	O
</s>
<s>
This	O
permissive	O
open	O
source	O
license	O
allows	O
its	O
integration	O
as	O
a	O
simulation	O
engine	O
into	O
several	O
—	O
proprietary	B-Application
or	O
free/libre	B-Application
—	O
EDA	O
tools	O
such	O
as	O
KiCad	B-Language
,	O
EAGLE	B-Language
(	O
program	O
)	O
,	O
CoolSPICE	B-Algorithm
,	O
Altium	B-Algorithm
and	O
.	O
</s>
<s>
Ngspice	B-Algorithm
has	O
a	O
command	O
line	O
input	O
interface	O
and	O
offers	O
plotting	O
capability	O
.	O
</s>
<s>
Recent	O
progresses	O
on	O
Ngspice	B-Algorithm
have	O
been	O
presented	O
at	O
conferences	O
such	O
as	O
FOSDEM	O
and	O
FSiC	O
.	O
</s>
