Document 267 SPICE Model – SER1590 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 SER1590 Power Inductors Part number SER1590-301 SER1590-501 SER1590-601 SER1590-681 SER1590-801 SER1590-901 SER1590-102 Frequency limit of model (MHz) ⏲) Lower Upper R1 (⏲ 0.1 10 263 0.1 10 301 0.1 10 235 0.1 10 272 0.1 10 300 0.1 10 412 0.1 10 535 LVAR Coefficients ⏲) R2 (⏲ 0.003 0.003 0.003 0.008 0.008 0.016 0.020 C (pF) 47.1 11.5 12.4 22.3 18.0 19.9 27.7 k1 2.12E-05 1.90E-06 3.06E-05 2.87E-05 2.90E-05 5.09E-05 1.00E-09 k2 0.126 0.195 0.140 0.229 0.600 0.364 0.341 k3 0.300 0.500 0.600 0.680 0.800 0.900 1.00 Specifications subject to change without notice. © Coilcraft, Inc. 2009 k4 4.19E-03 7.16E-03 6.80E-03 9.62E-03 8.50E-03 1.92E-02 1.20E-02 k5 9.85E-06 1.00E-05 9.40E-06 9.81E-06 1.94E-05 9.85E-06 1.00E-05 Document 267-24 Revised 08/06/04