Bipolar Junction Transistor (SPICE Gummel Poon)

In this topic:

Netlist Entry

Qxxxx collector base emitter [substrate] modelname [area] [OFF] [IC=vbe,vce]
[TEMP=local_temp] [M=mult] [DTEMP=dtemp]
collector Collector node name
base Base node name
emitter Emitter node name
substrate Substrate node name
modelname Name of model. Must begin with a letter but can contain any character except whitespace and '.'.
area Area multiplying factor. Area scales up the device. E.g. an area of 3 would make the device behave like 3 transistors in parallel. Default is 1.
OFF Instructs simulator to calculate operating point analysis with device initially off. This is used in latching circuits such as thyristors and bistables to induce a particular state. See .OP for more details.
vbe,vce Initial conditions for base-emitter and collector-emitter junctions respectively. These only have an effect if the UIC parameter is specified on the .TRAN statement (see .TRAN).
local_temp Local temperature. Overrides specification in .OPTIONS or .TEMP statements.
mult Device multiplier. Equivalent to putting mult devices in parallel.
dtemp Differential temperature. Similar to local_temp but is specified relative to circuit temperature. If both TEMP and DTEMP are specified, TEMP takes precedence.

NPN BJT Model Syntax

.model modelname NPN ( parameters )

PNP BJT Model Syntax

.model modelname PNP ( parameters )

Lateral PNP BJT Model Syntax

.model modelname LPNP ( parameters )

BJT Model Parameters

The symbols '???MATH???\times???MATH???' and '???MATH???\div???MATH???' in the Area column means that the specified parameter should be multiplied or divided by the area factor respectively.

Name Description Units Default Area
IS Transport saturation current A 1e-16 ???MATH???\infty???MATH???
BF Ideal maximum forward beta 100
NF Forward current emission coefficient 1.0
VAF, VA Forward Early voltage V ???MATH???\infty???MATH???
IKF, IK Corner for forward beta high current roll-off A ???MATH???\infty???MATH??? ???MATH???\infty???MATH???
ISE B-E leakage saturation current A 0 ???MATH???\infty???MATH???
NE B-E leakage emission coefficient 1.5
BR Ideal maximum reverse beta 1
NR Reverse current emission coefficient 1
VAR Reverse Early voltage V ???MATH???\infty???MATH???
IKR Corner for reverse beta high current roll-off A ???MATH???\infty???MATH??? ???MATH???\infty???MATH???
ISC B-C leakage saturation current A 0 ???MATH???\infty???MATH???
NC B-C leakage emission coefficient 2
NK, NKF 0.5
RB Zero bias base resistance ???MATH???\Omega???MATH??? 0
IRB Current at which base resistance falls halfway to its minimum value A ???MATH???\infty???MATH??? ???MATH???\infty???MATH???
RBM Minimum base resistance at high currents ???MATH???\Omega???MATH??? RB
RE Emitter resistance ???MATH???\Omega???MATH??? 0
RC Collector resistance ???MATH???\Omega???MATH??? 0
CJE B-E zero-bias depletion capacitance F 0 ???MATH???\infty???MATH???
VJE, PE B-E built in potential V 0.75
MJE, ME B-E junction exponential factor 0.33
TF Ideal forward transit time Sec. 0
XTF Coefficient for bias dependence of TF 0
VTF Voltage describing VBC dependence of TF V ???MATH???\infty???MATH???
ITF High-current parameter for effect on TF A 0 ???MATH???\infty???MATH???
PTF Excess phase at freq=1.0/(TF???MATH???\times 2\pi???MATH???) Hz degree 0
CJC B-C zero-bias depletion capacitance F 0 ???MATH???\infty???MATH???
VJC, PC B-C built-in potential V 0.75
MJC, MC B-C junction exponential factor 0.33
XCJC Fraction of B-C depletion capacitance connected to internal base node 1
TR Ideal reverse transit time Sec. 0
ISS Substrate diode saturation current A 0 ???MATH???\infty???MATH???
NS Substrate diode emission coefficient 1
CJS, CCS Zero-bias collector substrate capacitance F 0 ???MATH???\infty???MATH???
VJS, PS Substrate junction built-in potential V 0.75
MJS, MS Substrate junction exponential factor 0
XTB Forward and reverse beta temperature exponent 0
EG Energy gap eV 1.11
XTI Temperature exponent for effect on IS 3
FC Coefficient for forward-bias depletion capacitance formula 0.5
TNOM, TREF, t_measured Reference temperature; the temperature at which the model parameters were measured C 27
T_ABS If specified, defines the absolute model temperature overriding the global temperature defined using .TEMP C -
T_REL_ GLOBAL Offsets global temperature defined using .TEMP. Overridden by T_ABS C 0
KF Flicker noise coefficient 0
AF Flicker noise exponent 1.0
EF Flicker noise exponent 1.0
KFR Reverse flicker noise coefficient KF
AFR Reverse flicker noise exponent AF
EFR Reverse flicker noise exponent EF
NOISMOD Model selector. 1 (default) selects a corrected model for base shot and flicker noise. See to 0 for compatibility with earlier versions and other simulators 1
VO V 10.0
QCO Epitaxial region charge factor coulomb 0.0 ???MATH???\infty???MATH???
QUASIMOD Quasi saturation temperature flag:

QUASIMOD=0: no temperature dependence

QUASIMOD=1: temperature dependence enabled
RCO Epitaxial region resistance. Set to non-zero to enable quasi saturation model 0.0
GAMMA Epitaxial region doping factor 1e-11
VG Quasi saturation extrapolated bandgap voltage at 0K V 1.206
D Quasi saturation temp coeff for scattering limited hole carrier velocity NPN: 0.87

PNP :0.52
CN Quasi saturation temp coeff for hole mobility NPN: 2.42

PNP: 2.20
NEPI 1.0
SUBS If set to -1, device is lateral 1.0
TRE1 First order temperature coefficient, RE 0.0
TRE2 Second order temperature coefficient, RE 0.0
TRB1, TRB First order temperature coefficient, RB 0.0
TRB2 Second order temperature coefficient, RB 0.0
TRM1 First order temperature coefficient, RBM 0.0
TRM2 Second order temperature coefficient, RBM 0.0
TRC1, TRC First order temperature coefficient, RC 0.0
TRC2 Second order temperature coefficient 0.0

Hspice Temperature Parameters

The parameters defined in the following table are temperature coefficients and apply if the Hspice temperature model is enabled. This is the case if one or more of the following parameters are defined in the .MODEL statement:


If none of these parameters are specified, the standard (SPICE) temperature model is enabled and the following parameters have no effect.

Name Description Units Default
TLEV Temperature selector. Valid values are 0, 1, 2 or 3.
TLEVC Capacitance temperature selector. Valid values are 0, 1, 2 and 3
TIKF1 First order temperature coefficient, IKF
TIKF2 Second order temperature coefficient, IKF
TIKR1 First order temperature coefficient, IKR
TIKR2 Second order temperature coefficient, IKR
TIRB1 First order temperature coefficient, IRB
TIRB2 Second order temperature coefficient, IRB
TIS1 First order temperature coefficient, IS. (TLEV=3)
TIS2 Second order temperature coefficient, IS. (TLEV=3)
TBF1 First order temperature coefficient, BF
TBF2 Second order temperature coefficient, BF
TBR1 First order temperature coefficient, BR
TBR2 Second order temperature coefficient, BR
TISE1 First order temperature coefficient, ISE. (TLEV=3)
TISE2 Second order temperature coefficient, ISE. (TLEV=3)
TISC1 First order temperature coefficient, ISC. (TLEV=3)
TISC2 Second order temperature coefficient, ISC. (TLEV=3)
TISS1 First order temperature coefficient, ISS. (TLEV=3)
TISS2 Second order temperature coefficient, ISS. (TLEV=3)
TVAF1 First order temperature coefficient, VAF
TVAF2 Second order temperature coefficient, VAF
TVAR1 First order temperature coefficient, VAR
TVAR2 Second order temperature coefficient, VAR
TITF1 First order temperature coefficient, ITF
TITF2 Second order temperature coefficient, ITF
TTF1 First order temperature coefficient, TF
TTF2 Second order temperature coefficient, TF
TTR1 First order temperature coefficient, TR
TTR2 Second order temperature coefficient, TR
TNF1 First order temperature coefficient, NF
TNF2 Second order temperature coefficient, NF
TNR1 First order temperature coefficient, NR
TNR2 Second order temperature coefficient, NR
TNE1 First order temperature coefficient, NE
TNE2 Second order temperature coefficient, NE
TNC1 First order temperature coefficient, NC
TNC2 Second order temperature coefficient, NC
TNS1 First order temperature coefficient, NS
TNS2 Second order temperature coefficient, NS
TMJE1 First order temperature coefficient, MJE
TMJE2 Second order temperature coefficient, MJE
TMJC1 First order temperature coefficient, MJC
TMJC2 Second order temperature coefficient, MJC
TMJS1 First order temperature coefficient, MJS
TMJS2 Second order temperature coefficient, MJS
TVJE VJE temperature coefficient. (TLEVC ???MATH???\neq 0???MATH???)
TVJC VJC temperature coefficient. (TLEVC ???MATH???\neq 0???MATH???)
TVJS VJS temperature coefficient. (TLEVC ???MATH???\neq 0???MATH???)
CTE CJE temperature coefficient. (TLEVC ???MATH???\neq 0???MATH???)
CTC CJC temperature coefficient. (TLEVC ???MATH???\neq 0???MATH???)
CTS CJS temperature coefficient. (TLEVC ???MATH???\neq 0???MATH???)


The bipolar junction transistor model in SPICE 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 at high bias levels. The model will automatically simplify to the simpler Ebers-Moll model when certain parameters are not specified.

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 modelled by forward and reverse transit times, TF and TR, the forward transit time TF being bias dependent if desired, and non-linear 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 modelled by the beta temperature exponent XTB in the new model.

This implementation includes further enhancements to model quasi-saturation effects. This is governed by the model parameters RCO, QCO, GAMMA and for temperature dependence, QUASIMOD, VG, D and CN. The quasi-saturation model is compatible with PSpice. Hspice models may be accommodated by setting RC to zero and RCO to the value of RC in the Hspice model.


The Quasi-saturation model was developed from the following paper:

George M. Kull, Laurence W. Nagel, Shiuh-Wuu Lee, Peter Lloyd, E. James Prendergast and Heinz Dirks, "A Unified Circuit Model for Bipolar Transistors Including Quasi-Saturation Effects". IEEE Transactions on Electron Devices, Vol. ED-32, No 6 June 1985, pages 1103-1113