Winbond offers four-channel codec for short-loop VoIP

Winbond Electronics Corp. America introduces what the company claims is the industry's first four-channel codec optimized for short-loop VoIP.

"The market for these products is growing very, very steadily for the past five to six years. Primarily, that is due to the roll out of VoIP in the marketplace," notes Frank Dowling, director of product marketing, mixed signal systems, Winbond America.

The latest addition to Winbond's popular Pro-X (Programmble Extended) series, the W684386 is a highly integrated solution to support four FXS telephone line interfaces on a single low-power CMOS device.

"We started with a very good position in voice codecs, and a lot of our customers were starting to use the codecs in VoIP-type applications and they were asking us to also supply the SLCC type part of the circuitry as well," remarks Dowling. "What we have basically added to our codecs is what we call subscriber line controlled circuit. It is a little like SLCC but controlling some external components in order to create the SLCC effect."

Highly integrated
The W684386 leverages Winbond's proprietary codec/SLCC architecture. It is the "first four-channel device that incorporates a codec, SLCC functionality and a DC/DC converter functionality in a single chip," explains Dowling. "To control a telephone line, you need to have the SLCC functionality, which essentially provides all the high voltages on the line that you need to ring a phone or to detect when a phone goes off hook. The codec basically does the simple conversion from the analog phone signal to digital. We also have a programmable codec because we support a tremendous amount of signalling on the chip as well. Then the DC/DC converter?in supporting this kind of line, you need a lot of high voltages. The question is how do you provide those? By putting DC/DC converter control onto the chip, we found a way to supply those voltages onto the line."

Even though there is a high level of integration in the new product, Dowling is quick to point out that the device still has the best in-class performance. "We have the lowest idle channel noise in the industry [-92dB] and best return loss performance [42dB]."

The W684386 also offers various architecture options, "particularly for the DC/DC converter side," adds Dowling. "Basically it gives the customer a lot of flexibility on how they want to deploy the technology."

The W684386 is available now in a 128-QFP package at 44.50 (in 10,000 quantities) with full production scheduled in Q2.

Winbond is one of the exhibitors in the upcoming IIC-China 2008.