A 30V synchronous buck converter chip set—the IRF6631 Control MOSFET and IRF6638 Synchronous MOSFET—is claimed to offer a board space savings of almost 50% compared to other approaches using three SO-8 devices. Developed by International Rectifier, the chip set integrates the company's DirectFET packaging with double-sided cooling and the latest Hexfet MOSFET technology.
In addition to saving space, the chips improve efficiency by over 1% in the 5A to 8A range, says IR.
The IRF6631 DirectFET Control MOSFET reduces switching losses, while the IRF6638 DirectFET synchronous MOSFET lessens conduction losses and reverse-recovery charge.
The IRF6631 features a gate charge of 12nC and delivers a 16% reduction in figure of merit of on-resistance gate charge (99.6 mΩnC); the IRF6638 Synchronous FET delivers a typical on-state resistance of 3.0mΩ at 4.5V.