## Implementing Models in PSpice
The models are based only on steady-state AC measurements and analysis. No DC bias or transient analyses were verified. The GLaplace element is used in PSPICE to describe a frequency-dependent impedance. The impedance is given by the inverse of the XFORM, or XFORM = 1/Z(S). First, place a GLaplace element (part) into the model circuit schematic and connect as shown in the schematic below. Next, edit the GLaplace element by double-clicking on the part in your schematic. Click on the "XFORM =1/S" line and edit the value in the "value" box, as follows: ## For a frequency-dependent resistance (e.g. RVAR1, RVAR2)
Z(S) = RVAR1 = k1*sqrt(Frequency), where Frequency is in degrees Since S is the frequency in radians, Frequency must be converted to degrees. The resulting frequency-dependent resistance will be in Ohms units. 1/Z(S) = XFORM = 1/(k1*sqrt(S/(2*3.14159265))) ## For a frequency-dependent inductance (e.g. LVAR)
Z = S*LVAR = k3-(k4*LOG(k5*Frequency)), where Frequency is in degrees Since S is the frequency in radians, Frequency must be converted to degrees. Since the inductance is given in uH units, the LVAR expression is converted as shown below. 1/Z = XFORM = 1/(S*1e-6*( k3-(k4*LOG(k5*(S/(2*3.14159265)))))) ## Other circuit elementsPlace and wire the other parts of the model in the schematic. If the specific model inductance element is a fixed value inductor, use the IND part instead of the GLaplace part. Edit the part values to match those of the model table values for the specific inductor you are simulating. See the example schematic and netlist shown below. ## Example PSpice schematic and netlistIn the case where two GLaplace elements are in series, a large-valued resistance to ground (Rsim) was added to prevent a floating node error. The large-valued resistance (R3) was added to measure voltage across the entire model.
* Example Schematics Netlist * ## To view the specific effective simulation resultsInclude the following Macros in your Probe trace analysis to see frequency vs. inductance, impedance, phase angle (in degrees), and Q factor: PI = 3.14159265 |

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