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Updated documentation reflecting changed into bjt models.

pre-master-46
pnenzi 23 years ago
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      doc/ngspice.texi

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@ -3542,7 +3542,7 @@ conditions.
General form:
@example
DXXXXXXX n+ n- mname <area=val> <pj=val> <off> <ic=vd> <temp=val>
DXXXXXXX n+ n- mname <area=val> <m=val> <pj=val> <off> <ic=vd> <temp=val>
+ <dtemp=val>
@end example
@ -4030,7 +4030,8 @@ $$
General form:
@example
QXXXXXXX NC NB NE <NS> MNAME <AREA> <OFF> <IC=VBE, VCE> <TEMP=T>
QXXXXXXX nc nb ne <ns> mname <area=val> <areac=val> <areab=val>
+ <m=val> <off> <ic=vbe, vce> <temp=val> <dtemp=val>
@end example
@ -4043,18 +4044,22 @@ $$
NC, NB, and NE are the collector, base, and emitter nodes, respectively.
NS is the (optional) substrate node. If unspecified, ground is used.
MNAME is the model name, AREA is the area factor, and OFF indicates an
(optional) initial condition on the device for the dc analysis. If the
area factor is omitted, a value of 1.0 is assumed. The (optional)
initial condition specification using IC=VBE, VCE is intended for use
with the UIC option on the .TRAN control line, when a transient analysis
is desired starting from other than the quiescent operating point. See
the .IC control line description for a better way to set transient
initial conditions. The (optional) TEMP value is the temperature at
which this device is to operate, and overrides the temperature
specification on the .OPTION control line.
@option{nc}, @option{nb}, and @option{ne} are the collector, base, and
emitter nodes, respectively. @option{ns} is the (optional) substrate
node.If unspecified, ground is used. @option{mname} is the model name,
@option{area}, @option{areab}, @option{areac} are the area factors, and
@option{off} indicates an (optional) initial condition on the device
for the dc analysis. If the area factor is omitted, a value of 1.0 is
assumed. The (optional) initial condition specification using
@option{ic=vbe, vce} is intended for use with the @option{uic}
@command{.tran} control line, when a transient analysis is desired
starting from other than the quiescent operating point. See the
@command{.ic} control line description for a better way to set
transient initial conditions. The (optional) @option{temp} value is
the temperature at which this device is to operate, and overrides the
temperature specification on the @command{.option} control line. Using
@option{dtemp} option you can specify instance's temperature relative
to the circuit temperature.
@ -4062,7 +4067,19 @@ specification on the .OPTION control line.
@node BJT Models (NPN/PNP), Junction Field-Effect Transistors (JFETs), Bipolar Junction Transistors (BJTs), Transistors and Diodes
@subsection BJT Models (NPN/PNP)
NGSPICE provides two BJT device models. The @option{level} specifies the
model to be used:
@itemize @bullet
@item level=1 : This is the original spice BJT model, and it is the
default model if the @option{level} keyword is not
specified on the @command{.model} line.
@item level=2 : This is a modified version of the original spice
BJT that models both vertical and lateral devices and
includes temperature corrections of collector,
emitter and base resistors.
@end itemize
The bipolar junction transistor model in NGSPICE is an adaptation of the
integral charge control model of Gummel and Poon. This modified
Gummel-Poon model extends the original model to include several effects
@ -4073,93 +4090,141 @@ to be more easily understood by the program user, and to reflect better
both physical and circuit design thinking.
The dc model is defined by the parameters IS, BF, NF, ISE, IKF, and NE
which determine the forward current gain characteristics, IS, BR, NR,
ISC, IKR, and NC which determine the reverse current gain
characteristics, and VAF and VAR which determine the output conductance
for forward and reverse regions. Three ohmic resistances RB, RC, and RE
are included, where RB can be high current dependent. Base charge
storage is modeled by forward and reverse transit times, TF and TR, the
forward transit time TF being bias dependent if desired, and nonlinear
depletion layer capacitances which are determined by CJE, VJE, and MJE
for the B-E junction , CJC, VJC, and MJC for the B-C junction and CJS,
VJS, and MJS for the C-S (Collector-Substrate) junction. The
temperature dependence of the saturation current, IS, is determined by
the energy-gap, EG, and the saturation current temperature exponent,
XTI. Additionally base current temperature dependence is modeled by the
beta temperature exponent XTB in the new model. The values specified
are assumed to have been measured at the temperature TNOM, which can be
specified on the .OPTIONS control line or overridden by a specification
on the .MODEL line.
The dc model is defined by the parameters @option{IS}, @option{BF},
@option{NF}, @option{ISE}, @option{IKF}, amd @option{NE} which determine
the forward current gain characteristics, @option{IS}, @option{BR},
@option{NR}, @option{ISC}, @option{IKR}, and @option{NC} which determine
the reverse current gain characteristics, and @option{VAF} and @option{VAR}
which determine the output conductance for forward and reverse regions.
Level 2 model includes substrate staturation current @option{ISS}.
Three ohmic resistances @option{RB}, @option{RC}, and @option{RE}
are included, where @option{RB} can be high current dependent. Base charge
storage is modeled by forward and reverse transit times, @option{TF} and
@option{TR}, the forward transit time @option{TF} being bias dependent if
desired, and nonlinear depletion layer capacitances which are determined by
@option{CJE}, @option{VJE}, and @option{NJE} for the B-E junction, @option{CJC},
@option{VJC}, and @option{NJC} for the B-C junction and @option{CJS},
@option{VJS}, and @option{MJS} for the C-S (Collector-Substrate) junction.
Level 2 model defines a substrate capacitance that will be connected to
device's base or collector, to model lateral or vertical devices.
The temperature dependence of the saturation currents, @option{IS} and
@option{ISS} (for level 2 model), is determined by the energy-gap,
@option{EG}, and the saturation current temperature exponent, @option{XTI}.
Additionally base current temperature dependence is modeled by the beta
temperature exponent @option{XTB} in the new model. The values specified
are assumed to have been measured at the temperature @option{TNOM}, which
can be specified on the @command{.options} control line or overridden by
a specification on the @command{.model} line.
The BJT parameters used in the modified Gummel-Poon model are listed
below. The parameter names used in earlier versions of SPICE2 are still
accepted.
Modified Gummel-Poon BJT Parameters.
@multitable @columnfractions .1 .45 .15 .15 .15 .1
@item name @tab parameter @tab units @tab default @tab example @tab area
@item IS @tab transport saturation current @tab A @tab 1.0e-16 @tab
1.0e-15 @tab *
@item BF @tab ideal maximum forward beta @tab - @tab 100 @tab 100
@item NF @tab forward current emission coefficient @tab - @tab 1.0 @tab 1
@item VAF @tab forward Early voltage @tab V @tab infinite @tab 200
@item IKF @tab corner for forward beta current roll-off @tab A @tab
infinite @tab 0.01 @tab *
@item ISE @tab B-E leakage saturation current @tab A @tab 0 @tab 1.0e-13
@tab *
@item NE @tab B-E leakage emission coefficient @tab - @tab 1.5 @tab 2
@item BR @tab ideal maximum reverse beta @tab - @tab 1 @tab 0.1
@item NR @tab reverse current emission coefficient @tab - @tab 1
@tab 1
@item VAR @tab reverse Early voltage @tab V @tab infinite @tab 200
@item IKR @tab corner for reverse beta high current roll-off
@tab A @tab infinite @tab 0.01 @tab *
@item ISC @tab B-C leakage saturation current @tab A @tab 0 @tab 1.0e-13
@tab *
@item NC @tab B-C leakage emission coefficient @tab - @tab 2 @tab 1.5
@item RB @tab zero bias base resistance @tab Z @tab 0 @tab 100 @tab *
@item IRB @tab current where base resistance falls halfway to its min
value @tab A @tab infinite @tab 0.1 @tab *
@item RBM @tab minimum base resistance at high currents @tab Z @tab RB
10 @tab *
@item RE @tab emitter resistance @tab Z @tab 0 @tab 1 @tab *
@item RC @tab collector resistance @tab Z @tab 0 @tab 10 @tab *
@item CJE @tab B-E zero-bias depletion capacitance @tab F @tab 0 @tab
2pF @tab *
@item VJE @tab B-E built-in potential @tab V @tab 0.75 @tab 0.6
@item MJE @tab B-E junction exponential factor @tab - @tab 0.33 @tab 0.33
@item TF @tab ideal forward transit time @tab sec @tab 0 @tab 0.1ns
@item XTF @tab coefficient for bias dependence of TF @tab - @tab 0
@item VTF @tab voltage describing VBC dependence of TF @tab V @tab infinite
@item ITF @tab high-current parameter for effect on TF @tab A @tab 0
@tab *
@item PTF @tab excess phase at freq=1.0/(TF*2PI) Hz @tab deg @tab 0
@item CJC @tab B-C zero-bias depletion capacitance @tab F @tab 0 @tab
2pF @tab *
@item VJC @tab B-C built-in potential @tab V @tab 0.75 @tab 0.5
@item MJC @tab B-C junction exponential factor @tab - @tab 0.33 @tab 0.5
@item XCJC @tab fraction of B-C depletion capacitance connected to
Modified Gummel-Poon BJT Parameters:
@multitable @columnfractions .1 .40 .10 .15 .15 .1
@item name @tab parameter @tab units @tab default @tab example @tab scale factor
@item SUBS @tab substrate connection: 1 for
vertical geometry, -1 for
lateral geometry.
(level 2 only) @tab 1 @tab
@tab 1.0e-15 @tab
@item IS @tab transport saturation current @tab A @tab 1.0e-16
@tab 1.0e-15 @tab area
@item ISS @tab reverse saturation current,
substrate-to-collector for
vertical device or
substrate-to-base for lateral
(level 2 only) @tab A @tab 1.0e-16
@tab 1.0e-15 @tab area
@item BF @tab ideal maximum forward beta @tab - @tab 100 @tab 100
@item NF @tab forward current emission
coefficient @tab - @tab 1.0 @tab 1
@item VAF @tab forward Early voltage @tab V @tab infinite @tab 200
@item IKF @tab corner for forward beta
current roll-off @tab A @tab infinite
@tab 0.01 @tab area
@item ISE @tab B-E leakage saturation current @tab A @tab 0 @tab 1.0e-13
@tab area
@item NE @tab B-E leakage emission coefficient @tab - @tab 1.5 @tab 2
@item BR @tab ideal maximum reverse beta @tab - @tab 1 @tab 0.1
@item NR @tab reverse current emission coefficient @tab - @tab 1
@tab 1
@item VAR @tab reverse Early voltage @tab V @tab infinite @tab 200
@item IKR @tab corner for reverse beta high current roll-off
@tab A @tab infinite @tab 0.01 @tab area
@item ISC @tab B-C leakage saturation current
(area is "areab" for vertical
devices and "areac" for lateral) @tab A @tab 0
@tab 1.0e-13 @tab area
@item NC @tab B-C leakage emission coefficient @tab - @tab 2 @tab 1.5
@item RB @tab zero bias base resistance @tab Z @tab 0 @tab 100 @tab area
@item IRB @tab current where base
resistance falls halfway
to its min value @tab A @tab infinite @tab 0.1 @tab area
@item RBM @tab minimum base resistance at high currents @tab Z
@tab RB 10 @tab area
@item RE @tab emitter resistance @tab Z @tab 0 @tab 1 @tab area
@item RC @tab collector resistance @tab Z @tab 0 @tab 10 @tab area
@item CJE @tab B-E zero-bias depletion capacitance @tab F @tab 0
@tab 2pF @tab area
@item VJE @tab B-E built-in potential @tab V @tab 0.75 @tab 0.6
@item MJE @tab B-E junction exponential factor @tab - @tab 0.33 @tab 0.33
@item TF @tab ideal forward transit time @tab sec @tab 0 @tab 0.1ns
@item XTF @tab coefficient for bias dependence of TF @tab - @tab 0
@item VTF @tab voltage describing VBC dependence of TF @tab V @tab infinite
@item ITF @tab high-current parameter for effect on TF @tab A
@tab 0 @tab - @tab area
@item PTF @tab excess phase at freq=1.0/(TF*2PI) Hz @tab deg @tab 0
@item CJC @tab B-C zero-bias depletion capacitance
(area is "areab" for vertical
devices and "areac" for lateral) @tab F @tab 0
@tab 2pF @tab area
@item VJC @tab B-C built-in potential @tab V @tab 0.75 @tab 0.5
@item MJC @tab B-C junction exponential factor @tab - @tab 0.33 @tab 0.5
@item XCJC @tab fraction of B-C depletion capacitance connected to
internal base node @tab - @tab 1
@item TR @tab ideal reverse transit time @tab sec @tab 0 @tab 10ns
@item CJS @tab zero-bias collector-substrate capacitance @tab F @tab 0
@tab 2pF @tab *
@item VJS @tab substrate junction built-in potential @tab V @tab 0.75
@item MJS @tab substrate junction exponential factor @tab - @tab 0 @tab 0.5
@item XTB @tab forward and reverse beta temperature exponent @tab - @tab
@item TR @tab ideal reverse transit time @tab sec @tab 0 @tab 10ns
@item CJS @tab zero-bias collector-substrate capacitance
(area is "areac" for vertical devices and
"areab" for lateral) @tab F @tab 0
@tab 2pF @tab area
@item VJS @tab substrate junction built-in potential @tab V @tab 0.75
@item MJS @tab substrate junction exponential factor @tab - @tab 0 @tab 0.5
@item XTB @tab forward and reverse beta temperature exponent @tab - @tab
0
@item EG @tab energy gap for temperature effect on IS @tab eV @tab 1.11
@item XTI @tab temperature exponent for effect on IS @tab - @tab 3
@item KF @tab flicker-noise coefficient @tab - @tab 0
@item AF @tab flicker-noise exponent @tab - @tab 1
@item FC @tab coefficient for forward-bias depletion capacitance formula
@tab - @tab 0.5 @tab o
@item TNOM @tab Parameter measurement temperature @tab °C @tab 27 @tab 50
@item EG @tab energy gap for temperature effect on IS @tab eV @tab 1.11
@item XTI @tab temperature exponent for effect on IS @tab - @tab 3
@item KF @tab flicker-noise coefficient @tab - @tab 0
@item AF @tab flicker-noise exponent @tab - @tab 1
@item FC @tab coefficient for forward-bias depletion capacitance formula
@tab - @tab 0.5 @tab o
@item TNOM @tab Parameter measurement temperature @tab °C @tab 27 @tab 50
@item TRE1 @tab 1st order temperature coefficient for RE
(level 2 only) @tab 1/°C @tab 0.0 @tab 1e-3
@item TRE2 @tab 2nd order temperature coefficient for RE
(level 2 only) @tab 1/°C^2 @tab 0.0 @tab 1e-5
@item TRC1 @tab 1st order temperature coefficient for RC
(level 2 only )@tab 1/°C @tab 0.0 @tab 1e-3
@item TRC2 @tab 2nd order temperature coefficient for RC
(level 2 only) @tab 1/°C^2 @tab 0.0 @tab 1e-5
@item TRB1 @tab 1st order temperature coefficient for RB
(level 2 only) @tab 1/°C @tab 0.0 @tab 1e-3
@item TRB2 @tab 2nd order temperature coefficient for RB
(level 2 only) @tab 1/°C^2 @tab 0.0 @tab 1e-5
@item TRB1 @tab 1st order temperature coefficient for RBM
(level 2 only) @tab 1/°C @tab TRB1 @tab 1e-3
@item TRB2 @tab 2nd order temperature coefficient for RBM
(level 2 only) @tab 1/°C^2 @tab TRB2 @tab 1e-5
@end multitable
@node Junction Field-Effect Transistors (JFETs), JFET Models (NJF/PJF), BJT Models (NPN/PNP), Transistors and Diodes
@subsection Junction Field-Effect Transistors (JFETs)

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