Inductor coupling scheme to enhance the dynamic performance of a half-bridge DC-DC converter

The transformer concept has been adopted recently for the voltage regulator to improve the efficiency by extending the duty cycle. But the dynamic performance of the transformer based topologies is poor due to their low inductor current slew-rate and also due to the leakage inductance of the transformer. A fast transient converter is proposed, which employs coupled inductor scheme using a balancing winding to enhance the dynamic performance. In the present work, inductor coupling is introduced only during the transient period so that the steady state inductance remains unaffected. In this paper, the operation of the proposed power circuit and its theoretical analysis to derive a simple equivalent circuit are presented. A 12 V input, 1 V/60 A output, 450 kHz converter has been designed and simulated using SABER. The simulation results show considerable improvement in the dynamic performance.