International Rectifier Corp. (IR, El Segundo, CA) introduced a control and synchronous-switching chip set for high-frequency dc-dc converters powering next-generation processors in high-end advanced servers and desktop computers. Other applications include point-of-load dc-dc conversion in telecom and datacom systems.
The chip set pair delivers 84.5-percent efficiency at 90 A in a four-phase 1U (1.75 in height) VRM outline system switching at 750 kHz per phase, and 87-percent efficiency at 150 A in an eight-phase, embedded VRD10.2 design switching at 400 kHz per phase. Both devices feature IR’s patented DirectFET packaging technology.
The monolithic IRF6691 DirectFETKY™ integrates a Schottky diode and synchronous MOSFET into a single package to enable an efficiency improvement of 1.1 percent at 1 MHz per phase at full load. The IRF6617 DirectFET™ HEXFET control MOSFET features a low total gate charge (Qg of 11 nC), delivering a 33-percent reduction in on-resistance times gate charge product of 87 mOhm-nC at 4.5 VGS.
Both devices are available immediately. The IRF6691 DirectFETKY device is $1.49 each and the IRF6617 DirectFET MOSFET is $0.87 each; pricing for both devices is in 10,000-unit quantities.
