SPICE

Document 298
SPICE Model – 1812PS
This lumped-element (SPICE) model data simulates the
frequency-dependent behavior of Coilcraft ferrite surface
mount inductors within the frequency range shown in the
accompanying table.
The equivalent lumped element model schematic is
shown below. The element values R1, R2, C, L, k1 and k2
are listed in the table for each component value. The value
of the frequency-dependent variable resistor RVAR1 relates to the skin effect and is calculated from:
RVAR1 = k1 *
•
k1 is shown for each value in the accompanying table.
• f is the frequency in Hz
The value of the frequency-dependent variable resistor
RVAR2 relates to core losses and is calculated from:
RVAR2 = k2 *
•
•
k2 is shown for each value in the accompanying table.
f is the frequency in Hz
element model compared to the measurements taken of
the component.
Typically, the Self-Resonant Frequency (SRF) of the
component model will be higher than the measurement of
the component mounted on a circuit board. The parasitic
reactive elements of a circuit board or fixture will effectively
lower the circuit resonant frequency, especially for very
small inductance values. Since data sheet specifications
are based on typical production measurements, and the
SPICE models are based on de-embedded measurements
as described below, the model results may be different
from the data sheet specifications.
Lumped Element Modeling Method
Measurements were made using a 50 Ohm Agilent/
HP 4395A impedance analyzer with an Agilent/HP 16193
test fixture. Calibration was performed using open/short/
load standards. Fixture compensation was performed
using open and short standards.
The lumped element values were determined by matching
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.
The lumped element models were used to generate our
2-port S-parameters and therefore give identical results. The S-parameters are available on our web site
at http://www.coilcraft.com/models.cfm.
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 typical production verification instruments and fixtures.
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
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
Document 298-1 Revised 11/13/02
Document 298
SPICE Model for Coilcraft 1812PS Power Inductors
Part number
1812PS-102M
1812PS-152M
1812PS-222M
1812PS-272M
1812PS-332M
1812PS-392M
1812PS-472M
1812PS-562M
1812PS-682M
1812PS-103M
1812PS-153M
1812PS-223M
1812PS-333M
1812PS-393M
1812PS-473M
1812PS-683M
1812PS-823M
1812PS-104M
1812PS-124M
1812PS-154M
1812PS-224M
1812PS-334M
1812PS-474M
1812PS-564M
1812PS-684M
1812PS-824M
1812PS-105M
Frequency limit
of model (MHz)
Lower
Upper
0.1
300
0.1
60
0.1
60
0.1
55
0.1
50
0.1
50
0.1
50
0.1
45
0.1
40
0.1
40
0.1
35
0.1
25
0.1
20
0.1
20
0.1
18
0.1
13
0.1
11
0.1
11
0.1
9.0
0.1
8.0
0.1
6.0
0.1
4.0
0.1
3.0
0.1
1.5
0.1
1.0
0.1
1.0
0.1
1.0
R1
608
840
1600
1540
1690
2630
3320
3160
3910
6080
8370
7160
4160
4640
5110
2090
4010
2390
2660
1650
1060
1280
1180
1040
1120
620
674
R2
0.054
0.054
0.072
0.072
0.120
0.104
0.095
0.097
0.124
0.154
0.326
0.314
0.418
0.622
0.883
1.19
1.24
1.39
1.39
1.97
2.61
4.08
5.28
6.61
6.61
8.41
9.11
C (pF)
137
93
93
79
107
103
37.5
152
206
273
137
0.615
0.903
0.763
0.833
1.47
1.38
1.40
1.74
2.12
2.63
2.36
2.99
5.86
5.30
8.52
11.0
L (µH)
1.0
1.5
2.2
2.7
3.3
3.9
4.7
5.6
6.8
10
15
22
33
39
47
68
82
100
120
150
220
330
470
560
680
818
997
Specifications subject to change without notice.
© Coilcraft, Inc. 2009
k1
7.60E-07
3.75E-07
7.50E-07
7.50E-07
8.53E-07
2.30E-05
4.50E-05
5.68E-05
1.48E-05
2.96E-05
1.00E-07
3.98E-07
2.38E-07
2.38E-07
1.51E-04
3.50E-05
3.50E-05
1.75E-05
1.49E-05
2.51E-05
6.77E-05
1.23E-04
7.20E-05
7.20E-05
1.02E-04
1.02E-04
1.57E-04
k2
2.29
1.25
1.89
1.89
3.56
4.21
3.31
7.35
8.05
32.2
33.7
11.2
14.6
18.6
31.8
37.9
59.9
71.1
76.9
108
139
231
342
342
412
388
503
Document 298-5 Revised 02/05/03