A scheme for extracting transient model parameters

The accuracy of the SPICE transient model parameters is very important in designing switching circuits. In this paper, a method of extracting transient model parameters is presented. Based on the extraction of DC and AC model parameters, and taking the AC model parameters as the initial values, the more exact transient model parameters to fit four time constants (td, tr, ts and tf) can be extracted by using of Levenberg-Marquardt´s global optimization algorithm. The four calculated transient time constants have small difference with experimental data. This method is also valid for macro devices which are constructed with SPICE-based devices, and the computing time used for extraction is acceptable