SPICE

Document 267
SPICE Model – MLC
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 only be analyzed at
the input and output ports. Individual elements of the
model are not determined by parameter measurement.
The elements are determined by the overall performance of the lumped element model compared to the
measurements taken of the component.
• k3, k4, and k5 are shown in the accompanying table.
RVAR2
VAR
C
R2
RVAR1
VAR
R1
LVAR
• 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
• f is the frequency in Hz
• LVAR is the inductance in µH
• LOG is the natural LOG (base e)
Disclaimer
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. 2009
* LOG (k5 * f)
Document 267-1 Revised 03/17/09
Document 267
SPICE Model for Coilcraft MLC Power Inductors
Part number
MLC1265-361
MLC1260-401
MLC1255-421
MLC1240-451
MLC1265-701
MLC1250-801
MLC1240-901
MLC1260-122
MLC1255-122
MLC1250-132
MLC1245-152
MLC1245-402
MLC1565-501
MLC1555-551
MLC1560-901
MLC1538-102
MLC1550-102
MLC1538-152
MLC1550-252
MLC1555-302
MLC1550-452
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
100
0.1
100
0.1
100
0.1
60
0.1
100
0.1
100
0.1
100
0.1
100
0.1
90
0.1
80
0.1
70
0.1
60
0.1
50
LVAR Coefficients
⏲)
R1 (⏲
4
2
1
5
2
2
15
4
2
16
16
30
30
35
27
29
36
22
38
36
34
⏲)
R2 (⏲
0.00093
0.00093
0.00093
0.00173
0.00124
0.00235
0.00257
0.00238
0.00238
0.00238
0.00408
0.00818
0.00086
0.00134
0.00172
0.00346
0.00172
0.00436
0.00343
0.00406
0.00713
C (pF)
2.40
2.52
1.79
2.57
3.00
2.86
3.65
2.60
3.01
4.00
2.84
4.98
3.95
2.97
3.44
5.08
6.96
10.0
6.26
5.84
6.66
k1
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
k2
0.019
0.019
0.019
0.024
0.035
0.043
0.048
0.060
0.066
0.075
0.079
0.255
0.028
0.029
0.052
0.063
0.067
0.116
0.155
0.200
0.275
k3
0.36
0.40
0.42
0.45
0.70
0.80
0.90
1.2
1.2
1.3
1.5
4.0
0.50
0.55
0.90
1.0
1.0
1.5
2.5
3.0
4.5
Specifications subject to change without notice.
© Coilcraft, Inc. 2009
k4
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.003
0.005
0.041
0.001
0.003
0.007
0.009
0.009
0.016
0.025
0.036
0.036
k5
4.00E-06
4.00E-06
4.00E-06
4.00E-06
4.00E-06
4.00E-06
4.00E-06
2.00E-06
2.00E-06
5.00E-06
7.00E-06
9.00E-06
8.00E-06
8.00E-06
8.00E-06
9.00E-06
9.00E-06
9.40E-06
9.00E-06
9.30E-06
8.80E-06
Document 267-45 Revised 04/11/05