Predicting total harmonic distortion in asymmetric digital subscriber line transformers by simulation

As a design application, the asymmetric digital subscriber line (ADSL) broad-band line transformer offers somewhat different challenges than those in power supply design. In this paper, we use simulation to analyze total harmonic distortion (THD) as affected by the nonlinear behavior of the magnetic material in a line transformer. We use a mixed-technology model of the line transformer and circuit simulation to predict the level of THD for a variety of core types and configurations. A comparison of the simulation results with measured THD figures demonstrates the accuracy of the models.