Multiple output DC/DC zero-current switch quasi-resonant converter

Nowadays, launched electronic equipment need more and more energy which means a bigger volume of their power supplies, leading to more expense and more EMI generation. In order to reduce these constraints, new switchmode power supply principles have been proposed, using resonance in particular. But this concept is not well adapted to multi-output power supplies. This paper shows, within an industrial feasibility project, the problems inherent to the PWM technique and proposes a simple manufacturable structure of a DC-DC multi-output power converter, with a resonant main output rated (5 V/6 A) and two secondary outputs rated (/spl plusmn/15 V/1 A) of forward type. This half-bridge structure is zero current switched with a resonant frequency of 750 kHz. The bidirectional secondary current is consumed by synchronous rectifiers. Moreover this solution gives good efficiency even at low loads which is essential in such equipment.<>