A Low Profile Gate Drive Power Supply

Air core based PCB winding transformers are gaining wide attention due to low cost and size requirements. A novel application of this transformer is gate drive power supply with low power rating. In this paper, the application of a coreless PCB transformer into a synchronous flybuck converter is presented. It has been shown that use of phase reversal, interleaving and symmetry in winding arrangement can increase efficiency and reduce winding losses considerably. Part to part variation due to PCB design process has been eliminated by adding a secondary side referenced controller. The proposed transformer is capable of providing functional isolation between floating and ground plane referenced supply. Besides smaller footprint, this topology can eliminate cost and increase power density by inserting the winding within the substrate. EMC based analysis is also presented. In conclusion, a six sigma approach to designing planar transformers is presented.