Small power-conversion chips are alternative to quarter-bricks

Spencer Chin EBN (05/19/2003 10:00 AM EST)

Vicor Corp. earlier this month introduced a proprietary architecture for power component systems that the company said lowers cost while exhibiting higher density and performance.

Vicor's Factorized Power Architecture (FPA) uses small power-conversion components, called V-I chips, to carry out isolation, voltage conversion, regulation, and EMI suppression functions. The chips, packaged in small, lightweight BGAs, handle up to 200W and are designed as an alternative to quarter-brick converters, according to the Andover, Mass., power supplier.

"We look at this as a new way to configure power in a system--combining characteristics of distributed and intermediate bus architectures," said senior director of marketing Andy Hilbert.

Vicor is the second power supplier in recent weeks to announce an alternative approach to conventional converters for point-of-load applications. Power-One Inc., Camarillo, Calif., introduced its maXyz 3015P modules at the beginning of May.

But unlike Power-One's modules, which compete more closely with low-power chips from semiconductor suppliers, Vicor's parts compete with high-power converters for test and high-end computing and communications equipment, according to Hilbert.

The V-I chips come in two basic types. One is a preregulator module that takes an unregulated high-voltage output and produces a regulated output near the nominal input voltage. The other, a voltage transformation module, steps the bus voltage up or down with isolation to produce the required load voltage.

Hilbert said Vicor's approach provides regulation up front, and isolation and voltage transformation at the point of load. "This overcomes noise and ground loops to allow for faster transient response, with few or no external parts. You don't need holdup or bypass capacitors that are big and costly."

The ability of designers to step up from a lower voltage also overcomes the problem of intermediate bus voltages that are too low, Hilbert added.

According to Vicor, prices for the V-I chips start at 12 cents a watt, with a 200W voltage transformation module tagged at $25 in production quantities.

Vicor's FPA solution is cost-effective for high-power, single-output applications, according to analysts.

Stephens Inc., Little Rock, Ark., estimates in a report that Vicor's FPA solution would cost $50 for a 60A, 3.3V output, compared with $90 for an intermediate bus architecture based on conventional point-of-load converters. But the intermediate bus architecture is less expensive for lower-power outputs, the report said.

Because Vicor's parts have their own pinout, second sources won't be initially available, although Hilbert said that licensing the technology to other suppliers is a future possibility.

The first V-I chip offered is a bus converter module, which delivers an isolated 12V input from a preregulated 48V bus. The module is sampling, and the preregulator module will begin sampling the third quarter.