SPICE

Document 267
SPICE Model – LPS4018
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 LPS4018 Power Inductors
Part number
LPS4018-561
LPS4018-102
LPS4018-222
LPS4018-332
LPS4018-472
LPS4018-682
LPS4018-103
LPS4018-153
LPS4018-183
LPS4018-223
LPS4018-333
LPS4018-473
LPS4018-683
LPS4018-104
LPS4018-124
LPS4018-154
LPS4018-184
LPS4018-224
LPS4018-334
LPS4018-474
LPS4018-564
LPS4018-684
LPS4018-824
LPS4018-105
LPS4018-155
LPS4018-185
LPS4018-225
LPS4018-335
Frequency limit
of model (MHz)
Lower Upper
0.1
100
0.1
100
0.1
100
0.1
100
0.1
80
0.1
80
0.1
60
0.1
40
0.1
40
0.1
40
0.1
40
0.1
40
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
8
0.1
8
0.1
8
0.1
8
0.1
6
0.1
4
0.1
3
0.1
2
LVAR Coefficients
⏲)
R1 (⏲
450
550
180
120
160
120
170
240
14
180
8
20
55
10
15
11
10
18
50
15
50
20
30
25
200
210
400
430
⏲)
R2 (⏲
0.030
0.040
0.070
0.080
0.125
0.150
0.200
0.260
0.270
0.360
0.420
0.650
0.950
1.40
1.60
2.00
2.50
3.70
5.90
7.10
10.0
11.5
14.0
16.5
25.0
31.5
32.5
48.0
C (pF)
1.40
0.850
1.34
2.26
3.08
1.70
2.98
3.42
2.14
3.70
2.47
2.47
2.28
3.43
3.13
2.94
3.15
2.70
3.40
3.50
3.97
3.66
3.43
3.93
3.54
3.65
3.49
3.53
k1
1.40E-04
1.20E-04
4.00E-05
1.80E-04
2.00E-04
2.50E-04
2.20E-04
1.70E-04
1.00E-03
2.70E-04
7.00E-04
6.90E-04
7.80E-04
8.80E-04
1.20E-03
2.00E-03
2.30E-03
4.00E-03
3.90E-03
4.40E-03
4.40E-03
3.50E-03
3.80E-03
8.40E-03
2.00E-03
2.10E-02
2.20E-02
5.80E-03
k2
0.275
0.195
0.500
0.792
0.890
1.92
2.05
2.31
4.31
4.24
6.90
11.4
15.0
20.0
24.0
30.0
36.0
50.0
80.0
100
115
145
150
200
330
525
700
950
k3
0.56
1.0
2.2
3.3
4.7
6.8
10
15
18
22
33
47
68
100
120
150
180
220
330
470
560
680
820
1000
1500
1800
2200
3300
Specifications subject to change without notice.
© Coilcraft, Inc. 2006
k4
0.010
0.010
0.024
0.083
0.100
0.160
0.163
0.170
0.310
0.210
0.538
0.653
0.760
1.81
1.52
2.29
2.60
2.78
4.63
7.54
6.80
9.88
11.4
13.1
20.2
21.4
21.4
22.5
k5
9.10E-06
9.00E-06
9.40E-06
9.80E-06
9.70E-06
9.90E-06
9.80E-06
9.75E-06
9.70E-06
9.80E-06
9.84E-06
9.90E-06
9.89E-06
9.97E-06
9.96E-06
9.96E-06
1.00E-05
1.00E-05
1.02E-05
1.03E-05
1.06E-05
1.06E-05
1.07E-05
1.11E-05
1.16E-05
1.20E-05
1.35E-05
1.94E-05
Document 267-48 Revised 08/29/06