SPICE

Document 267
SPICE Model – MSS1038
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 MSS1038 Power Inductors
Part number
MSS1038-152
MSS1038-252
MSS1038-382
MSS1038-522
MSS1038-702
MSS1038-103
MSS1038-123
MSS1038-153
MSS1038-183
MSS1038-223
MSS1038-273
MSS1038-333
MSS1038-393
MSS1038-473
MSS1038-563
MSS1038-683
MSS1038-823
MSS1038-104
MSS1038-124
MSS1038-154
MSS1038-184
MSS1038-224
MSS1038-274
MSS1038-334
MSS1038-394
MSS1038-474
MSS1038-564
MSS1038-684
MSS1038-824
MSS1038-105
Frequency limit
of model (MHz)
Lower Upper
0.1
100
0.1
80
0.1
80
0.1
60
0.1
40
0.1
40
0.1
40
0.1
30
0.1
30
0.1
30
0.1
20
0.1
20
0.1
20
0.1
20
0.1
20
0.1
20
0.1
10
0.1
10
0.1
10
0.1
10
0.1
10
0.1
10
0.1
10
0.1
10
0.1
6
0.1
6
0.1
4
0.1
4
0.1
3
0.1
3
LVAR Coefficients
⏲)
R1 (⏲
190
115
100
150
230
260
210
215
215
105
125
125
140
75
65
25
130
30
135
30
110
150
55
75
100
50
105
75
200
210
⏲)
R2 (⏲
0.008
0.010
0.013
0.022
0.027
0.035
0.041
0.050
0.065
0.073
0.089
0.093
0.112
0.128
0.180
0.213
0.261
0.304
0.380
0.506
0.582
0.756
0.926
1.090
1.141
1.243
1.696
1.926
2.596
2.853
C (pF)
2.45
3.47
3.86
3.69
3.04
3.11
3.90
3.46
3.28
4.69
5.17
4.90
4.04
5.12
5.03
4.98
4.16
3.94
4.86
4.28
4.54
5.16
6.28
5.31
6.10
5.10
7.38
6.72
8.26
8.08
k1
2.50E-04
1.50E-04
1.90E-04
1.00E-04
4.00E-04
3.00E-04
2.00E-04
2.00E-04
2.00E-04
2.50E-04
2.20E-04
2.50E-04
3.00E-04
5.00E-04
4.00E-04
7.00E-04
3.50E-04
2.50E-04
5.00E-05
1.50E-04
5.00E-04
5.00E-04
4.00E-04
5.00E-04
5.00E-04
7.00E-04
6.00E-04
5.00E-04
6.00E-04
7.00E-04
k2
k3
0.36
1.5
0.90
2.5
1.10
3.8
2.10
5.2
4.80
7.0
4.80
10
5.00
12
6.45
15
6.75
18
6.75
22
10.0
27
10.0
33
11.0
39
11.5
47
14.7
56
16.3
68
24.0
82
24.0
100
32.0
120
32.0
150
76.0
180
78.0
220
110
270
110
330
140
390
135
470
200
560
245
680
320
820
400
1000
Specifications subject to change without notice.
© Coilcraft, Inc. 2006
k4
0.038
0.038
0.040
0.040
0.060
0.078
0.088
0.120
0.140
0.150
0.230
0.230
0.290
0.570
0.660
0.842
0.842
0.693
0.700
0.800
0.760
1.31
1.04
1.03
1.52
1.69
2.90
3.73
3.75
5.94
k5
9.50E-06
9.70E-06
9.70E-06
9.80E-06
9.80E-06
9.80E-06
9.85E-06
9.90E-06
9.90E-06
9.90E-06
9.98E-06
9.98E-06
9.95E-06
9.95E-06
1.00E-05
9.98E-06
1.01E-05
1.01E-05
1.03E-05
1.03E-05
1.07E-05
1.07E-05
1.18E-05
1.23E-05
1.26E-05
1.28E-05
1.36E-05
1.38E-05
1.78E-05
1.70E-05
Document 267-53 Revised 11/01/06