ABSTRACT
The design of the integrated planar transformer must be carried out as part of the main system printed circuit board design process. Design and development of the integrated planar transformer is the most expensive and time consuming of all of the types considered but potentially yields the best performance results. There are four main variations of planar transformer to consider: integrated, standard discrete, custom discrete, and discrete stackable element (DSE). The basic design of a DSE planar transformer follows a similar process to that for the discrete Off-the-shelf transformer. In wirewound high-frequency transformers, skin effects are a real concern, requiring an application-specific choice of Litz wire to be used in most examples. The design process for a full custom integrated or discrete planar transformer to meet the requirements of a particular application comprises two stages: the electrical design and the mechanical design.
