IR Introduces 30V-DirectFET MOSFET Chipset for dc-dc Buck Converters
International Rectifier Corp. (IR®) has introduced a new 30V-synchronous buck converter chipset consisting of the IRF6631 Control MOSFET and IRF6638 Synchronous MOSFET. The pair features IR's benchmark DirectFET® packaging with double-sided cooling and the latest HEXFET® MOSFET technology to reach higher levels of efficiency and thermal performance at the intermediate current levels (below 18A). Applications include advanced notebook and desktop computer, telecom, datacom and general purpose synchronous buck designs where small size, high efficiency, and improved thermal conduction result in increased power density.
"This new DirectFET chipset is an excellent choice for designers seeking very compact and efficient switching in mid-range, 15- to 18A power converter applications. In addition to improving efficiency by over 1% in the 5 to 8A range, the board space savings is almost 50% compared to the typical approaches using three SO-8 devices," said Jeff Sherman, senior marketing manager of IR's Portable Computing Solutions.
Each device is tailored to maximize performance in its role within synchronous dc-dc buck converter circuits. The IRF6631 DirectFET Control MOSFET reduces switching losses, while the IRF6638 DirectFET synchronous MOSFET lessens conduction losses and reverse-recovery charge.
The IRF6631 Control FET features a gate charge of 12nC and delivers a 16 percent reduction in figure of merit of on resistance-gate charge (99.6 mOhm-nC) compared to previous offerings. The IRF6638 Synchronous FET delivers a typical on-state resistance of 3.0 mOhm at 4.5V, a 12% reduction over existing devices while maintaining the same gate charge.
