SPICE

Document 267
SPICE Model – MSS4020
This lumped-element (SPICE) model data simulates the
frequency-dependent behavior of Coilcraft power inductors within the frequency range shown in the accompanying table for each individual inductor.
The data represents de-embedded measurements, as
described below. Effects due to different customer circuit board traces, board materials, ground planes or
interactions with other components are not included and
can have a significant effect when comparing the simulation to measurements of the inductors using other
production verification instruments and fixtures.
The value of the frequency-dependent variable resistor
RVAR1 is calculated from:
RVAR1 = k1 *
• k1 is shown for each value in the accompanying table.
• f is the frequency in Hz
• RVAR1 is the resistance in Ohms
The value of the frequency-dependent variable resistor
RVAR2 is calculated from:
RVAR2 = k2 *
Lumped Element Modeling Method
• k2 is shown for each value in the accompanying table.
Measurements were made using a 50 Ohm impedance
analyzer. Fixture compensation was performed to remove fixture effects. No DC bias current was applied in
any of the measurements. The lumped element values
were determined by optimizing the simulation model to
an average of the measurements. This method results in
a model that represents as closely as possible the typical
frequency-dependent behavior of the component within
the model frequency range.
• f is the frequency in Hz
The equivalent lumped element model schematic is
shown below. Each model should be analyzed only at
the input and output ports. Conclusions based on individual lumped element values may be erroneous.
• k3, k4, and k5 are shown in the accompanying table.
• RVAR2 is the resistance in Ohms
Note: The log function in the following equation is the
natural logarithm, base e, not base 10.
The value of the frequency-dependent inductance LVAR
is calculated from:
LVAR = k3 − k4
* LOG (k5 * f)
• f is the frequency in Hz
• LVAR is the inductance in µH
• LOG is the natural LOG (base e)
Disclaimer
RVAR2
VAR
C
R2
RVAR1
VAR
R1
LVAR
Coilcraft makes every attempt to provide accurate measurement data and software, representative of our components, in a usable format. Coilcraft, however, disclaims
all warrants relating to the use of its data and software,
whether expressed or implied, including without limitation any implied warranties of merchantability or fitness
for a particular purpose. Coilcraft cannot and will not be
liable for any special, incidental, consequential, indirect
or similar damages occurring with the use of the data
and/or software.
Specifications subject to change without notice.
© Coilcraft, Inc. 2007
Document 267-1 Revised 08/03/07
Document 267
SPICE Model for Coilcraft MSS4020 Power Inductors
Part number
MSS4020-332
MSS4020-472
MSS4020-562
MSS4020-682
MSS4020-822
MSS4020-103
MSS4020-123
MSS4020-153
MSS4020-183
MSS4020-223
MSS4020-273
MSS4020-333
MSS4020-393
MSS4020-473
MSS4020-563
MSS4020-683
MSS4020-823
MSS4020-104
Frequency limit
of model (MHz)
Lower Upper
0.1
100
0.1
100
0.1
100
0.1
100
0.1
100
0.1
100
0.1
100
0.1
100
0.1
90
0.1
90
0.1
90
0.1
90
0.1
80
0.1
70
0.1
60
0.1
50
0.1
50
0.1
50
LVAR Coefficients
⏲)
R1 (⏲
55
50
35
35
33
37
43
10
11
11
11
12
15
12
10
22
14
8
⏲)
R2 (⏲
0.085
0.115
0.130
0.175
0.190
0.210
0.280
0.330
0.360
0.480
0.560
0.620
0.820
0.930
1.20
1.33
1.50
2.10
C (pF)
0.840
0.874
0.852
0.955
0.807
0.938
0.860
0.896
1.15
1.03
1.04
1.06
0.847
1.11
1.15
1.27
1.22
1.09
k1
k2
1.00E-07 0.544
1.00E-07 0.964
1.00E-07 1.00
1.00E-07 1.27
1.00E-07 1.45
1.00E-07 1.90
1.00E-07 1.90
1.00E-05 2.40
1.00E-05 2.98
1.00E-05 3.75
1.00E-05 4.25
1.00E-05 5.14
1.00E-05 5.78
1.00E-05 7.40
1.00E-05 9.23
1.00E-05 9.70
1.00E-05 9.78
1.00E-05 13.7
k3
3.3
4.7
5.6
6.8
8.2
10
12
15
18
22
27
33
39
47
56
68
82
100
Specifications subject to change without notice.
k4
0.080
0.144
0.192
0.232
0.281
0.411
0.497
0.497
0.728
0.881
0.881
1.29
1.27
1.27
1.54
2.05
2.97
2.98
k5
9.82E-06
9.88E-06
9.85E-06
9.84E-06
9.84E-06
9.86E-06
9.84E-06
9.44E-06
9.83E-06
9.84E-06
9.84E-06
9.85E-06
9.83E-06
9.83E-06
9.84E-06
9.83E-06
9.82E-06
9.83E-06
Document 267-34 Revised 11/09/04