EL SEGUNDO, CA. September 1998 - Extending its commitment to developing topology-specific solutions to customer power problems, International Rectifier (IR) now offers a family of HEXFET^® power MOSFETs rated from 500 to 650 Volts that delivers the highest efficiency available in mass production today for switch mode power supply applications.

These new devices feature on-resistance (RDS(on)) ratings as much as 50 percent lower than previous devices for optimum conduction efficiency in this voltage range in the same package outline, balanced with gate charge (Qg) characteristics that are reduced about one-third to achieve lower switching and drive losses. The new HEXFETs can reduce power losses within a power supply by as much as 30 percent, facilitating either a smaller heat sink and/or cooler operation within the existing thermal system. They are implemented using established IR process technology and manufactured in volume in IR's HEXFET America facility in Temecula, CA -- the world's largest power MOS production facility.

"In the power supply industry, obtaining MOSFETs with optimum efficiency, high reliability and low cost is the key to success," said Chris Ambarian, director of technical marketing for MOSFETs and IGBTs at IR. "Our new topology-specific high-voltage HEXFET devices extend our leadership position as the world's leading supplier of MOSFETs for switching power supplies, providing unrivaled efficiency and reliability at very attractive prices. They are companions to the recently announced low-voltage devices that shattered previous benchmarks for efficiency in power supplies for mobile Pentium II microprocessors and other DC/DC and synchronous rectifier applications."

Examples of the level of improvement are:

On-Resistance Improvements

Voltage Rating	Existing IR Parts	Existing RDS(on)	New IR Devices	New RDS(on)	RDS(on) Reduction	Package Type
500 V	IRF840	0.85W	IRFB11N50A	0.52W	39%	TO-220
500 V	IRFI840G	0.85W	IRFIB7N50A	0.52W	39%	FullPak-220
500 V	IRFP460	0.27W	IRFPS37N50A	0.13W	50%	TO-247
600 V	IRFBC40	1.2W	IRFB9N60A	0.75W	38%	TO-220
600 V	IRFBC40G	1.2W	IRFIB6N60A	0.75W	38%	FullPak-220
600 V	IRFBC40L	1.2W	IRFSL9N60A	0.75W	38%	TO-262
600 V	IRFBC40S	1.2W	-->IRFS9N60A	0.75W	38%	D2Pak
650 V			IRFB9N65A	0.9W		TO-220
650 V			IRFIB5N65A	0.9W		FullPak-220

Gate Charge Improvements

Voltage Rating	Existing IR Parts	Existing Qg	New IR Devices	New Qg	Qg Reduction	Package Type
500 V	IRF840	63 nC	IRFB11N50A	49 nC	22%	TO-220
500 V	IRFP460	210 nC	IRFP22N50A	140 nC	33%	TO-262
600 V	IRFBC40	60 nC	IRFB9N60A	49 nC	18%	TO-220

Continuing the trend started earlier this year, the new devices feature topology-specific data sheets that provide more useful ratings to the SMPS designer. The devices are characterized for several parameters at conditions seen in actual SMPSs, providing a much better indication of how they will actually operate in-circuit. Part numbers for the new series have also become more engineer-friendly, providing actual current ratings at a glance.

All new devices have already been qualified and are in full production. Data sheets are available either on International Rectifier's website (www.irf.com) or Fax-On-Demand system (310-252-7100 USA and 44 1883 783420 Europe).