Schematic of Spice Gummel–Poon model NPN
The Gummel–Poon model is a model of the bipolar junction transistor . It was first described in an article published by Hermann Gummel and H. C. Poon at Bell Labs in 1970.[ 1]
The Gummel–Poon model and modern variants of it are widely used in popular circuit simulators such as SPICE . A significant effect that the Gummel–Poon model accounts for is the variation of the transistor
β β -->
F
{\displaystyle \beta _{\text{F}}}
and
β β -->
R
{\displaystyle \beta _{\text{R}}}
values with the direct current level. When certain parameters are omitted, the Gummel–Poon model reduces to the simpler Ebers–Moll model .[ 1]
Model parameters
Spice Gummel–Poon model parameters[ 2]
#
Name
Property modeled
Parameter
Units
Default value
1
IS
current
transport saturation current
A
1× 10 −16
2
BF
current
ideal max. forward beta
—
100
3
NF
current
forward-current emission coefficient
—
1
4
VAF
current
forward early voltage
V
∞
5
IKF
current
corner for forward-beta high-current roll-off
A
∞
6
ISE
current
B–E leakage saturation current
A
0
7
NE
current
B–E leakage emission coefficient
—
1.5
8
BR
current
ideal max. reverse beta
—
1
9
NR
current
reverse-current emission coefficient
—
1
10
VAR
current
reverse early voltage
V
∞
11
IKR
current
corner for reverse-beta high-current roll-off
A
∞
12
ISC
current
B–C leakage saturation current
A
0
13
NC
current
B–C leakage emission coefficient
—
2
14
RB
resistance
zero-bias base resistance
Ω
0
15
IRB
resistance
current where base resistance falls half-way to its minimum
A
∞
16
RBM
resistance
minimum base resistance at high currents
Ω
RB
17
RE
resistance
emitter resistance
Ω
0
18
RC
resistance
collector resistance
Ω
0
19
CJE
capacitance
B–E zero-bias depletion capacitance
F
0
20
VJE
capacitance
B–E built-in potential
V
0.75
21
MJE
capacitance
B–E junction exponential factor
—
0.33
22
TF
capacitance
ideal forward transit time
s
0
23
XTF
capacitance
coefficient for bias dependence of TF
—
0
24
VTF
capacitance
voltage describing VBC dependence of TF
V
∞
25
ITF
capacitance
high-current parameter for effect on TF
A
0
26
PTF
excess phase at frequency = 1/(2π TF)
°
0
27
CJC
capacitance
B–C zero-bias depletion capacitance
F
0
28
VJC
capacitance
B–C built-in potential
V
0.75
29
MJC
capacitance
B–C junction exponential factor
—
0.33
30
XCJC
capacitance
fraction of B–C depletion capacitance connected to internal base node
—
1
31
TR
capacitance
ideal reverse transit time
s
0
32
CJS
capacitance
zero-bias collector–substrate capacitance
F
0
33
VJS
capacitance
substrate–junction built-in potential
V
0.75
34
MJS
capacitance
substrate–junction exponential factor
—
0
35
XTB
forward- and reverse-beta temperature exponent
—
0
36
EG
energy gap for temperature effect of IS
eV
1.1
37
XTI
temperature exponent for effect of IS
—
3
38
KF
flicker-noise coefficient
—
0
39
AF
flicker-noise exponent
—
1
40
FC
coefficient for forward-bias depletion capacitance formula
—
0.5
41
TNOM
parameter measurement temperature
°C
27
See also
References
External links
Bell System Technical Journal, v49: i5 May-June 1970 on archive.org
Designers-Guide.org comparison paper Xiaochong Cao, J. McMacken, K. Stiles, P. Layman, Juin J. Liou, Adelmo Ortiz-Conde, and S. Moinian, "Comparison of the New VBIC and Conventional Gummel–Poon Bipolar Transistor Models," IEEE Trans-ED 47 #2, Feb. 2000.