SPICE

Document 158
SPICE Model – 1008LS
This lumped-element (SPICE) model data simulates the
frequency-dependent behavior of Coilcraft RF surface
mount inductors from 1 MHz to the upper frequency limit
shown in the accompanying table.
The equivalent lumped element model schematic is shown
below. The element values R1, R2, C, and L are listed
for each component value. The value of the frequencydependent variable resistor RVAR relates to the skin effect
and is calculated from:
RVAR = k *
• k is shown for each value in the accompanying table.
• f is the frequency in Hz
Table 1. Test Gap
Size
0302
0402,0403
0603
0805
1008
1206
1812
Gap Width (inch / mm)
0.017 / 0.432
0.017 / 0.432
0.026 / 0.660
0.040 / 1.016
0.060 / 1.524
0.080 / 2.032
0.120 / 3.048
(50 Ohm) wide traces of tinned gold over 25 mil thick
alumina, and were not included in the gap. The TRL*
calibration plane is also illustrated in Figure 1.
Pad
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
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
The measurements were made over a brass ground
plane with each component centered over an air gap,
as illustrated in Figure 1. The gap width for each size
component is given in Table 1. The test pads were 30 mil
Air gap
Pad
Brass
ground
plane
Calibration
plane
Figure 1. Test Setup
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 up to a frequency just above
the self-resonant frequency of the model.
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.
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.
US +1-847-639-6400 [email protected]
UK +44-1236-730595 [email protected]
Taiwan +886-2-2264 3646 [email protected]
China +86-21-6218 8074 [email protected]
Singapore + 65-6484 8412 [email protected]
Document 158-1 Revised 11/08/13
© Coilcraft Inc. 2014
This product may not be used in medical or high
risk applications without prior Coilcraft approval.
Specification subject to change without notice.
Please check web site for latest information.
Document 158
SPICE Model for Coilcraft 1008LS Chip Inductors
Upper
R1R2
limit
Part number ()() C (pF) L (nH)
k
(MHz)
1008LS-102 150 0.62 0.21
10007.00E-04
1008LS-122 369 0.60 0.158 12007.41E-04
1008LS-152 369 0.70 0.185 15007.61E-04
1008LS-182 384 0.80 0.186 18008.40E-04
1008LS-222 384 1.10 0.168 22009.40E-04
1008LS-272 426 1.20 0.181 27001.25E-03
1008LS-332 261 1.40 0.309 33001.45E-03
1008LS-392 252 1.50 0.349 39001.47E-03
1008LS-432 100 1.70 0.350 43001.20E-02
1008LS-472 273 1.60 0.285 47001.79E-03
1008LS-502 125 2.20 0.300 50001.80E-02
1008LS-562 179 1.80 0.370 56002.06E-03
1008LS-622 100 2.50 0.390 62001.00E-02
1008LS-682 242 2.00 0.345 68002.82E-03
1008LS-822 224 2.60 0.445 82003.47E-03
1008LS-912 60 2.90 1.10
91002.30E-02
1008LS-103 300 2.90 0.385 100003.89E-03
1008LS-123 100 3.30 0.620 120002.20E-02
1008LS-153 90 3.70 0.820 150003.40E-02
1008LS-183 50 4.00 2.00 180003.20E-02
1008LS-223 80 6.14 0.960 220003.70E-02
1008LS-273 60 6.45 3.80 270003.50E-02
1008LS-333 125 7.00 0.800 330005.50E-02
1008LS-393 15010.0 0.520 390006.00E-02
1008LS-473 7510.7 2.70 470004.50E-02
1008LS-563 5010.0 5.10 560005.00E-02
1008LS-683 7513.5 4.20 680007.00E-02
1008LS-104 6020.5 7.50 1000006.30E-02
1000
500
400
400
400
300
200
170
200
170
200
140
200
130
110
200
100
200
200
200
100
80
100
100
100
50
50
50
US +1-847-639-6400 [email protected]
UK +44-1236-730595 [email protected]
Taiwan +886-2-2264 3646 [email protected]
China +86-21-6218 8074 [email protected]
Singapore + 65-6484 8412 [email protected]
Document 158-15 Revised 03/07/14
© Coilcraft Inc. 2014
This product may not be used in medical or high
risk applications without prior Coilcraft approval.
Specification subject to change without notice.
Please check web site for latest information.