Fabless Power-Device Challenger Emerges At APEC

March 27, 2008

Can the fabless semiconductor company model work as well for power devices as it does for more complex chips? It has for Alpha and Omega Semiconductor (AOS), which emerged from the shadows at APEC 2008 in Austin, Texas, last month with a

Don Tuite

Can the fabless semiconductor company model work as well for power devices as it does for more complex chips? It has for Alpha and Omega Semiconductor (AOS), which emerged from the shadows at APEC 2008 in Austin, Texas, last month with a successful product portfolio.

These devices include power MOSFETs, some unique transient-voltage supressors (TVS), and an array of high power-density dc-dc regulators, smart load switches, and battery-protection ICs. And it’s not a paper portfolio, either. Formed in 2000, AOS shipped more than 2.1 billion products last year, capturing almost $200 million in revenue.

The company’s founders, including CEO Mike Chang, comprise former Siliconix employees who departed when Vishay acquired Siliconix. The current management team also includes veterans from Linear, Elantec, Fairchild, National Semiconductor, Harris, Intersil, and Micrel. Chief technology officer Francois Hebert said the company developed its customer base, along with its product line, by starting with MOSFETs for laptops and working from there into a range of consumer products.

The company’s MOSFETs are now into a fourth generation of trench vertical depletion-mode devices, scaling for low conduction loss and die size. The 30-V, 85-A AOL1412 is designated a “softrecovery” device because it integrates a Schottky rectifier across its intrinsic body diode. Guaranteed maximum R_DS(ON) is less than 3.9 mO with 10 V of gate drive, less than 4.6 mO with 4.5 V.

While the MOSFETs are built on all-MOS process technologies, the company’s latest transient voltage supressors combine bipolars with its trench-MOS devices, yielding near-ideal clamping with low parasitics. Clearly, AOS is doing more with the fabless semiconductor model than simply relying on foundries’ standard recipes and cells.

So how will AOS differentiate its technologies so successfully with no fab of its own? Herbert points to the years of experience—and the PhDs—of the management team. “If you understand the process technology, you can make it work,” he says.

ALPHA AND OMEGA SEMICONDUCTOR www.aosmd.com