El Segundo, Calif.—Touting a breakthrough in high-density power conversion, International Rectifier's IR38xx SupIRBuck family of point-of-load (POL) voltage regulators integrate HEXFET (trench) MOSFETs and a synchronous buck control IC in a 5-by-6 mm Power QFN package, thus shrinking the silicon footprint by 70 percent over discrete solutions. At the same time, SupIRBuck, working over substantially larger input and output voltages than most competing regulators, claims between 8 to 10 percent higher full-load efficiency than monolithic ICs.
"Because SupIRBuck has a unique, scalable common footprint, designers can simply 'cut and paste' their design to significantly reduce risk and enable faster time-to-market," said Tim Phillips, vice president of the Enterprise Power Business Unit. "The addition of the SupIRBuck POL family to IR's XPhase and DirectFET multiphase architecture allows us to provide the most efficient and complete power solution for the data center including enterprise servers."
Departing from both the monolithic regulator approach (high density but not flexible, poor efficiency at 12 volts), and the discrete-IC with external MOSFET (flexible but large board area required and high parts count), IR's strategy is to combine an optimized MOSFET for the task with a PWM IC in what might be best described as a micro-module (i.e., without inductors and capacitors) in about the size of an SO-8. The SupIRBuck solution takes up just 30 mm2 of board area, versus about 100 mm2 for a discrete solution using a 3-by-3 mm IC and two SO-8 FETs. The board savings is about 35 percent over a discrete solution using a dual SO-8 FET.
The regulators are designed to deliver four, six, seven, nine, and 12 amps in 9 versions (with various options) at voltages down to 0.6 volt. As for power performance, overall efficiency for the IR3821 operating at 5 volts (input and output) is 86 percent at 8 amps to 91 percent at 2 amps (and about 88 percent at 1 amp). Operating efficiencies for the IR3820 operating at 3.3 volts output for a 12-volt input ranges from about 87 percent at 2 amps to 92 percent at 6 amps to 90 percent at 12 amps.
The 600-kHz IR38xx operates from a 2.5 to 21 volt input. Features include pre-bias start up, precise output voltage regulation, hiccup current limiting, and thermal shutdown. Optional features include tracking, programmable power good, and 300-kHz operation to provide an additional two amps output. The SupIRBuck family's thermally enhanced package, with a 0.9 mm profile, allows mounting on the backside of the motherboard, making the devices suited for space constrained, high-density server applications.
Pricing: Begins at $2.25 each in 10k quantities; pricing subject to change. Production orders are available immediately.
Datasheet: IR3810; IR3811; IR3812; IR3820; IR3821; IR3822
International Rectifier, 1-310-252-7105, www.irf.com