120 Comparison of Two Layered and Three Layered Coreless Printed Circuit Board Step-Down Power Transformers

In this paper the comparative results of two layered and three layered coreless Printed Circuit Board (PCB) step down 2:1 power transformers operating in MHz frequency were addressed. The two different step down transformers approximately having same self inductances, one in two layer and the other in three layer were designed and evaluated for the given power transfer application. The performance characteristics of these transformers under similar conditions were measured and the comparative parameters of these transformers in terms of their resistances, self, leakage, mutual inductances, and coupling coefficient are analyzed. For the given output power, the measured energy efficiency of the three layered transformer is improved by 3% and the area is reduced by 32% compared to two layered transformer. The efficiency of the three layered transformer is 94.5% approximately for an output power level of 25W at an operating frequency of 2.5MHz.