APPLICATION NOTE 4596

Improve Two-Phase Buck Converter Performance with a Coupled-Choke Topology

By: Sunil Akre

Abstract: Interleaved multiphase converters or synchronous buck converters are usually employed to supply power to microprocessors. However, these designs typically have large ripple currents in their inductors, and thus the converters will have relatively high switching losses. One alternative that reduces switching losses is to use a coupled-choke topology in the multiphase converter. The coupled chokes improve supply efficiency by reducing the phase ripple without increasing the output ripple voltage. Furthermore, the combination of the coupled-choke topology and a lower leakage inductance will also improve the converter's transient response.