Freewheeling Diode Characteristic

In the Freewheeling Diode Characteristics dialog box, each tab corresponds to one freewheeling diode characteristic curve, that is, I_f = f(V_f) at a specific junction temperature T_j. These characteristics are obtained from the forward diode characteristic supplied by the device manufacturer as illustrated below.

• Use the Characteristic Data section to enter curves or work with the data for a specific curve selected on the tabs.
• Use the Boundary Conditions section to specify the junction temperature (T_j) associated with each curve.
• Use the Fitting Ranges section to specify the range of the data to use when performing the fitting. Initially, the values are filled with the maximum current and voltage values from the curve.
• In the Fitting Characteristic Order section, you must specify two sets of characteristic data. The characteristic under nominal junction temperature is mandatory, while the characteristic at a different temperature is used to calculate correction coefficients when the junction temperature of the device is different from the nominal temperature. If the data for the latter are not available, select Not Used from the drop-down list.
• In the Fitting section, you perform the fitting of the model to the characteristic curve data and validate the results. In addition, select the Disable Diode check box to disable the use of the diode in the model.

For more information, click an area on the image below.

When finished, click Next to continue characterizing the device (IGBT Thermal Model).