LLC resonant converter for 48 V to 0.9 V VRM

48 V to 0.9 V VRM using LLC resonant converter is presented. ZVS is realized for switches and the converter can operate at higher frequency. How to reduce primary current amplitude by reducing power factor angle is explored. The effect of secondary leakage inductance is studied and FEA method is used to find the optimal transformer winding con figuration. The resonant inductor can be integrated with transformer primary leakage inductance, which reduces the total magnetic component counts. A prototype of 48 V to 0.9 V/50 A VRM is built to verify the result.

[1]  F. Lee,et al.  LLC resonant converter for front end DC/DC conversion , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[2]  Bryan M. H. Pong,et al.  Practical solutions to the design of current-driven synchronous rectifier with energy recovery from current sensing , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[3]  F.C. Lee,et al.  Over current protection methods for LLC resonant converter , 2003, Eighteenth Annual IEEE Applied Power Electronics Conference and Exposition, 2003. APEC '03..

[4]  F. C. Lee,et al.  A high power density, high efficiency and fast transient voltage regulator module with a novel current sensing and current sharing technique , 1999, APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285).

[5]  Peng Xu,et al.  A high efficiency topology for 12 V VRM-push-pull buck and its integrated magnetics implementations , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[6]  Fred C. Lee,et al.  1MHz Multi-Resonant Push-Pull 48V VRM , 2003 .

[7]  F.C. Lee,et al.  A MOSFET resonant synchronous rectifier for high-frequency DC/DC converters , 1990, 21st Annual IEEE Conference on Power Electronics Specialists.

[8]  J.A. Cobos,et al.  New driving scheme for self driven synchronous rectifiers , 1999, APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285).

[9]  Peng Xu,et al.  Single magnetic push-pull forward converter featuring built-in input filter and coupled-inductor current doubler for 48 V VRM , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).