From 3cef27f2fe8cbb5d1761d1fb347edd0d54b02a9c Mon Sep 17 00:00:00 2001 From: pnenzi Date: Sun, 2 Nov 2003 14:16:21 +0000 Subject: [PATCH] Updated documentation reflecting changed into bjt models. --- doc/ngspice.texi | 245 ++++++++++++++++++++++++++++++----------------- 1 file changed, 155 insertions(+), 90 deletions(-) diff --git a/doc/ngspice.texi b/doc/ngspice.texi index 03650c631..2211ab948 100644 --- a/doc/ngspice.texi +++ b/doc/ngspice.texi @@ -3542,7 +3542,7 @@ conditions. General form: @example - DXXXXXXX n+ n- mname + DXXXXXXX n+ n- mname + @end example @@ -4030,7 +4030,8 @@ $$ General form: @example - QXXXXXXX NC NB NE MNAME + QXXXXXXX nc nb ne mname + + @end example @@ -4043,18 +4044,22 @@ $$ -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)