Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Power/Alternative Energy
Power/Alternative Energy??

DC/DC buck converter improves efficiency, thermal performance

Posted: 27 Jul 2006 ?? ?Print Version ?Bookmark and Share

Keywords:IR? DC/DC buck converter? IRF6631? IRF6638? MOSFET?

International Rectifier (IR) has introduced a new 30V synchronous buck converter chipset consisting of the IRF6631 Control MOSFET and IRF6638 Synchronous MOSFET. IR said the pair features the company'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, 15-18A power converter applications. In addition to improving efficiency by over 1 percent in the 5-8A range, the board space savings is almost 50 percent compared to the typical approaches using three SO-8 devices," said Jeff Sherman, senior marketing manager for 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 milliohms nC) compared to previous offerings. The IRF6638 Synchronous FET delivers a typical on-state resistance of 3 milliohms at 4.5V, a 12 percent reduction over existing devices while maintaining the same gate charge.

IR said its patented DirectFET MOSFET packages present a whole new set of design advantages not previously delivered by standard plastic discrete packages. Their metal can construction is said to enable dual-side cooling that effectively doubles the current handling capacity of high frequency DC/DC buck converters powering advanced microprocessors. In addition, devices in the DirectFET package are compliant with the RoHS directive.

The IRF6631 and IRF6638 DirectFET MOSFETs are available immediately. Pricing is 65 cents each for the IRF6631 and $1.05 each for the IRF6638, both in 10,000-unit quantities. Prices are subject to change. The devices are RoHS compliant.

Article Comments - DC/DC buck converter improves effici...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top