•ꢀ LOGꢀisꢀtheꢀnaturalꢀLOGꢀ(basee)
Document 558
SPICE Model – 0603AF
This lumped-element (SPICE) model data simulates the
frequency-dependent behavior of Coilcraft RF inductors
within the frequency range shown in the accompanying
table for each individual inductor.
R
VAR2
C
R1
The data represents de-embedded measurements, as
described below.Effects due to different customer circuit
board traces, board materials, ground planes or interac-
tions 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.
L
R2
R
VAR1
VAR
The value of the frequency-dependent variable resistor
RVAR1 is calculated from:
Lumped Element Modeling Method
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.
R
VAR1 = k1 *
•ꢀ k1ꢀisꢀshownꢀforꢀeachꢀvalueꢀinꢀtheꢀaccompanyingꢀtable.
•ꢀ fꢀisꢀtheꢀfrequencyꢀinꢀHz
•ꢀ RVAR1 is the resistance in Ohms
Measurements were also taken on a network analyzer
over a brass ground plane with the component centered
over an air gap with a width of 0.026 inch (0.66 mm), as
illustrated in Figure 1.The test pads were 30 mil (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.
The value of the frequency-dependent variable resistor
RVAR2 is calculated from:
RVAR2 = k2 *
•ꢀ k2ꢀisꢀshownꢀforꢀeachꢀvalueꢀinꢀtheꢀaccompanyingꢀtable.ꢀ
•ꢀ fꢀisꢀtheꢀfrequencyꢀinꢀHz
•ꢀ RVAR2 is the resistance in Ohms
The value of the frequency-dependent inductance LVAR
is calculated from:
LVAR = k3 − k4 * LOG (k5 * f)
•ꢀ k3,ꢀk4,ꢀandꢀk5ꢀareꢀshownꢀinꢀtheꢀaccompanyingꢀtable.
•ꢀ fꢀisꢀtheꢀfrequencyꢀinꢀHz
Air gap
Pad
Pad
Brass
ground
plane
•ꢀ LVARꢀisꢀtheꢀinductanceꢀinꢀµH
Calibration
plane
Figure 1.Test Setup
Disclaimer
Coilcraft makes every attempt to provide accurate mea-
surement data and software, representative of our com-
ponents, in a usable format.Coilcraft, however, disclaims
all warrants relating to the use of its data and software,
whether expressed or implied, including without limita-
tion 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.
The lumped element values were determined by optimiz-
ing the simulation model to an average of the measure-
ments.This method results in a model that represents as
closely as possible the typical frequency-dependent be-
havior of the component within the model frequency range.
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 ele-
ments are determined by the overall performance of the
lumped element model compared to the measurements
taken of the component.
Document 558-1 Revised 07/26/11