Electrical and thermal performance of PWB transformers

The authors use analytical tools developed to predict the high-frequency characteristics of conventionally wound transformers and apply them to the planar printed wiring board (PWB) transformer case. The authors present a simple modeling technique that is useful in calculating the temperature rise for a PWB transformer assuming conduction through the base of the device as the only thermal path. These two simple techniques-while not completely rigorous for any planar device-prove to be quite adequate for first-cut analysis of practical devices. A case study using a 12-layer PWB transformer demonstrates that simple analytical solutions provide sufficient accuracy for practical designs.<>