black box modeling of ldmosfet
DESCRIPTION
Black Box Modeling of LDMOSFET. H. Taher, D. Schreurs and B. Nauwelaers. TELEMIC Devices & Circuits Group. Contents. Introduction Capacitive effects on terminal currents Constructing the model Validation of the model Conclusions. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
20/9/2004 1
Black Box Modeling of LDMOSFET
H. Taher, D. Schreurs and B. Nauwelaers
TELEMIC Devices & Circuits Group
20/9/2004 2
Contents
• IntroductionIntroduction
• Capacitive effects onon terminal currents
• Constructing the model
• Validation of the model
• Conclusions
20/9/2004 3
Modeling does not depend on S-parameters simulations Device is described by dynamical model The model used is BSIM3v3: Ns=2,Ws=80 um, Temp=27C
Introduction
Resistive dependence Capacitive dependence Inductive dependence
ANN
),...)(),(),...,(),(),(),(()( 21212122 tititvtvtvtvfti
),...)(),(),...,(),(),(),(()( 21212111 tititvtvtvtvfti
20/9/2004 4
Contents
• Introduction
• Capacitive effects on terminal currentsCapacitive effects on terminal currents
• Constructing the model
• Validation of the model
• Conclusions
20/9/2004 5
Device in circuit simulator with 50 Ohm load
DCblock
+ VD20V
DCfeed1 RlDCfeed
DCblock
+
-
f150MHz1V + VG
1.2V
DMOS
20/9/2004 6
Dependence of drain current on voltage derivative
),(2 dgd VVfI
Constructed from DC simulations
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0.004
29.85 29.9 29.95 30 30.05 30.1
vd V
id A
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0.004
0 0.5 1 1.5
vg V
id A
20/9/2004 7
Dependence of gate current on voltage derivative
Constructed from time domain simulations
))(),(),(),(()( 1 tvtvtvtvfti dgdgg
-0.00025-0.0002
-0.00015-0.0001
-0.000050
0.00005
0.00010.00015
0.00020.00025
29.85 29.9 29.95 30 30.05 30.1
vd V
ig A
-0.00025-0.0002
-0.00015-0.0001
-0.000050
0.00005
0.00010.00015
0.00020.00025
0 0.5 1 1.5
vg V
ig A
20/9/2004 8
Contents
• Introduction
• Capacitive effects on terminal currents
• Constructing the modelConstructing the model
• Validation of the model
• Conclusions
20/9/2004 9
Constructing the behavioral model
Circuit used in collecting Id data
+
-
f1GHz20V
DMOS
+ VG1.2V
+
-
f150MHz1V
DCblock
DCfeedDCfeed
+ VD20V
DCblock
Circuit used in collecting Ig data
05
1015202530354045
0 0.5 1 1.5 2 2.5
Vg V
Vd
V
DC ANO DATA
DMOS
+VG
+VD
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ANN Model
Inputs
Hidden layerHidden layer
1 2
1 2 3
1 2
NxInput layer
OutputOutput layerlayer
Outputs3-layer3-layer MLPMLP
i
k
j
Xi
k
x
ikiik
N
wx
1
)(kk gz
N z
kjkkj vzy
1
N s
i
iin xxY YU
1
2)(),()(
)(min
U
Tkjkki
)1(
1)(
eg
Nz
Ny
20/9/2004 11
Properties of ANN model
• Id model is – 3layers MLP
– 12 neurons hidden layer
– Test error less than 1%
• Ig model is– 3layers MLP
– 16 neurons hidden layer
– Test error less than 1%
20/9/2004 12
Contents
• Introduction
• Capacitive effects on terminal currents
• Constructing the model
• Validation of the modelValidation of the model
• Conclusions
20/9/2004 13
Drain current obtained from BSIM3v3 modelDrain current obtained from ANN model
Comparison between the drain current output from ANN model
and output from BSIM3v3
0
0.005
0.01
0.015
0.02
0.025
0 10 20 30 40
Vd VId
A
0
0.005
0.01
0.015
0.02
0.025
0 10 20 30 40
Vd V
Id A
Vg=3.5 V
Vg=1 V
20/9/2004 14
Comparison between the gate current output from ANN model
and output from BSIM3v3
5 10 15 20 25 30 350 40
0
20
40
60
-20
80
VdDC
i1.i, m
A
Outside the trained region
Vg=3.5 V
Vg=1 V
20/9/2004 15
VgDC=1.0V, vgac=0.3sin(2*pi*150E+6)V, VdDC=30V
Comparison between time domain drain current output from ANN
model and output from BSIM3v3
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0.004
0 5E-09 1E-08 2E-08
Time Sec
Dra
in C
urr
ent
A
ANN Model
BSIM3v3 Model
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2 4 6 8 10 120 14
300
400
500
600
200
700
time, nsec
ts(i1
.i), u
A
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.00.0 4.5
100
200
300
400
0
500
freq, GHz
i1.i,
uA
Comparison between time domain gate current output from ANN model and output
from BSIM3v3
20/9/2004 17
S-Parameters ComparisonS11 S12
S21
Vgs=1 V, Vds=30 V
S22
1
20/9/2004 18
Contents
• Introduction
• Capacitive effects on terminal currents
• Constructing the model
• Validation of the model
• ConclusionsConclusions
20/9/2004 19
Conclusions
• We presented a behavioral model for LDMOSFET based on ANN
• A good agreement between the responses of it with the corresponding outputs from BSIM3v3 model
• As a future work we will try to include the effect of the temperature in the model