Document 343 -1 Transmission Line Model These transmission line models accurately simulate the frequency-dependent behavior of Coilcraft surface mount "Spring" air core inductors within the frequency limits shown in the accompanying table for each individual inductor. They are based on de-embedded measurements using a 2-port network analyzer. Table 1. Test Gap Size Size A Size B The model schematic, shown below, combines an ideal transmission line model with lumped elements. Each model should be analyzed only as a whole at the input and output ports. Conclusions based on individual lumped element values may be erroneous. The individual element values R1, R2, C, Z0, EL, and F0 are listed in the table for each individual spring inductor. C P1 50 Ohm TL1 Z0 EL F0 Mini SpringsTM Gap Width (inch / mm) 0.060 / 1,524 0.120 / 3,048 Pad Air gap Pad Brass ground plane Calibration plane R1 Figure 1. Test Setup R2 P2 50 Ohm Effects due to different circuit board traces, board materials, ground planes or interactions with other components are not included. They will have a significant effect when comparing the simulation to measurements of the individual inductors using other production verification instruments and fixtures. Typically, the Self-Resonant Frequency (SRF) of the inductor model will be higher than a 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. Data sheet specifications are based on typical production measurements. These models are based on de-embedded 2-port measurements as described below, so 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 (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 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 specified frequency limits of the model. The lumped element models were used to generate our 2-port S-parameters and therefore give identical results with the same number of simulation frequency points. 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. Specifications subject to change without notice. Document 343-1 Revised 05/21/03 Document 343 -2 Transmission Line Model for Coilcraft Mini SpringsTM Part number A01T_ A02T_ A03T_ A04T_ A05T_ B06T_ B07T_ B08T_ B09T_ B10T_ Frequency limit of Model (MHz) Lower Upper 50 50 50 50 50 50 50 50 50 50 14000 9000 5500 4500 3500 4000 3500 2500 2500 2300 R1 ( ) R2 ( ) C (pF) Z0 ( ) TL1 EL (degrees) F0 (MHz) 11.13 11.55 6.809 7.084 5.363 14.85 16.69 26.68 22.30 17.51 0.0150 0.0320 0.0513 0.0807 0.1202 0.1508 0.1778 0.2304 0.2802 0.3509 0.0904 0.1114 0.1508 0.2621 0.2456 0.1234 0.1329 0.1247 0.1390 0.1866 94.13 116.7 144.2 182.9 213.8 182.5 203.6 225.3 254.5 269.3 33.44 34.19 39.01 38.39 39.56 40.64 44.14 48.11 50.75 49.99 3505 2218 1957 1572 1279 1184 1143 1082 1021 882 Specifications subject to change without notice. Document 343-2 Revised 05/21/03