With rising demands for higher power density, power-supply vendors are introducing dc-dc converters in a new format—the eighth-brick. With a typical footprint of 2.28 by 0.78 in., it's about 40% smaller than standard quarter-bricks. Eighth-bricks are rated for up to about 15 A (20 in a few instances), or about 50 W. Outputs as high as 75 W may be possible with efficiencies up to and above 90%.
Outputs will run from about 1 to 15 V, though not all vendors will offer the full range. Likewise, the 36- to 75-V input range (48 V nominal) is typical. Some vendors are also planning 12- and 24-V inputs. Besides these variations, packaging dimensions may vary slightly, with heights ranging from 0.26 to 0.4 in.
When introduced late in 2000, Vicor's PowerStick provided up to 75 W in a 2.28- by 0.5-in. unit with a nonstandard pinout and mounting style. But the recent eighth-bricks are more clearly scaled-down quarter-bricks with the same pinout. Datel announced its ULE series in the quarter-brick pinout. Subsequently, Celestica and di/dt introduced their eighth-bricks with the same pinout.
Power One now has an eighth-brick. Moreover, third-quarter launches are expected from SynQor, C&D Technologies, Cherokee International, Astrodyne, and Artesyn Technologies. Even Vicor may repackage its PowerStick in the eighth-brick format as early as this summer. Meanwhile, Betadyne plans a second-quarter introduction of a 2.01- by 0.78-in., 50-W converter in both a standard eighth-brick pinout and in a pinout with two sync pins.
For details, see www.artesyn.com, www.astrodyne.com, www.beta-dyne.com, www.dc-dc.com (C&D Technologies), www.celestica.com, www.cherokeellc.com, www.datel.com, www.didt.com, www.power-one.com, www.synqor.com, and www.vicr.com.