Ready or not, here come OC-768 components

SAN MATEO, Calif.—Despite an ongoing drought in long-haul demand, component makers old and new are ready with OC-768 (40-Gbit/second) devices, many of which will be shown at next week's Optical Fiber Communication Conference in Anaheim, Calif.

Some of the devices come from familiar names such as Infineon Technologies AG and Applied Micro Circuits Corp., but OC-768 startups will storm the OFC conference as well, undeterred by the slowdown in communications spending.

Most of the 40-Gbit/s devices won't be tackling the glamorous long-haul market immediately. It's long been assumed that OC-768 will see its first uses not in the network core, but in the very short reach (VSR) span between boxes, or even in the backplane. That was due to the complex physics of long-haul, 40-Gbit/s transmission, but it seems the economy might delay the long-haul market even further, say several aspiring OC-768 vendors.

That delay might actually prove helpful, some think.

"The market is not present today for 40 Gbit/second. On the other hand, the industry needs more time than initially believed to understand the issues of running 40 Gbit/second serial," said Oswin Schreiber, senior product marketing manager for AMCC (San Diego). "This [extra] time definitely will be needed."

Infineon this week announced what appears to be the first OC-768 framer and pointer processor to sample to customers. The CMOS-based device is designed to handle serial 40-Gbit/s data or four streams of 10 Gbit/s each.

One customer who has received samples was ready to test the framer on a line card early this month, and boards featuring the chip might be demonstrated at OFC, said Subodh Toprani, vice president of marketing at Infineon.

Toprani said with some pride that Infineon had edged out the competition. "It's the first time in the framer business that AMCC has not been first," he said. AMCC is expected to announce its OC-768 framer at OFC, however.

Indium phosphide foray

Separately, several OC-768 components companies will test the waters at OFC, many of them specializing in indium phosphide (InP) parts.

Fabless startup Inphi Corp. will show a family of transimpedance amplifiers (TIAs), which are used on the receiving end of an optical connection, as well as fully functional multiplexer and demultiplexer chips. The devices follow on the family of 40-Gbit/s laser drivers that Inphi announced in February.

Inphi will introduce two 43-Gbit/s TIAs: the 4332TA for links with optical amplification; and the 4330TA for links without. The company also will show the 5030TA, a 50-Gbit/s part for ultra-long-haul and submarine connections.

The TIAs are being sold as bare die. Inphi is willing to help customers integrate the TIAs with photodiodes, as is common with 10 Gbit/s solutions, but it's not clear that a standard integrated part is warranted, the company said. "We would consider it in the future, but at this point we believe there are performance advantages you can get by leaving them as discrete devices," said Gary Franzosa, Inphi's director of marketing. "It's very difficult to get a high enough inductance [between the devices] on-chip."

AMCC's Schreiber agreed that the TIA and PIN diode shouldn't necessarily be integrated. "As you integrate, you definitely increase the chip size — which is an issue for III-V components, because the material is very brittle," he said.

But startup Xindium Technologies Inc. is taking the opposite approach, having recently an integrated a TIA and PIN diode in InP. Whether one approach ends up better than another will depend on the trade-offs among several parameters, as is typical in analog design, Franzosa said.

Elsewhere, T-Networks Inc., an InP house developing 10- and 40-Gbit/s devices, announced Monday (March 11) that it already has design wins that will lead to volume production and revenue shipments in the third quarter of 2002. Likewise, OEpic Corp. this week announced four InP OC-768 parts strictly for the VSR market: a 850-nm laser and laser driver for transmission; and a limiting amplifier and an integrated receiver and transimpedance amplifier for the receiving side. The company expects to produce 1,310- and 1,550-nm lasers, more appropriate for metropolitan networking, by the end of the year.