Next-generation MSA divides parallel fiber-optic module makers into two camps
By KATHLEEN RICHARDS
A new multisource agreement in the parallel fiber-optic transmitter and receiver module market will standardize the next-generation packaging of three vendors.
W.L. Gore & Associates, Mitel Semiconductor, and Agilent Technologies announced a multisource agreement (MSA) involving a common package and interface specifications for 12-channel parallel fiber-optic modules. The MSA defines the package outline, front-panel cutout, printed-circuit-board footprint, electrical and optical interfaces, and general performance characteristics.
Operating at speeds as high as 2.5 Gbits/sec per channel, parallel fiber-optic modules are designed to interconnect large-scale networking equipment rack-to-rack or board-to-board using ribbon fiber cable. Available in 1x4 or 1x12 configurations, the transmitter modules incorporate vertical-cavity surface-emitting lasers (VCSELs).
In a market where availability has been one of the biggest issues to date, a move toward standard specifications bodes well for OEMs. This year, the 12-channel fiber-optic parallel module market will reach $89 million worldwide, according to ElectroniCast Corp. (San Mateo, CA). "It is supply-constrained; if people could ship more, the market would be higher," says Dale Murray, a senior analyst with ElectroniCast. "Supply should catch up in 18 months or less, depending on how fast manufacturers can ramp up." The market is expected to reach $659 million worldwide by 2004, according to ElectroniCast's estimates.
However, when next-generation products debut later this year, vendors in the category will effectively split into two camps. The market leader is Infineon Technologies (San Jose, CA). Infineon offers the 12-channel parallel-optical-link (PAROLI), which is designed according to the specifications in an earlier MSA with W.L. Gore & Associates. Gore's current offering is compliant with the Infineon/Gore MSA. Meanwhile, Molex licensed the PAROLI technology from Infineon in August, gaining the right to manufacture, market, and sell PAROLI modules.
"Infineon's got board position just about anywhere that anybody's using a parallel transmitter and receiver pair-they've been out there far longer than anyone. They were the first company to ship in volume production," says Murray. The Infineon design has a perimeter contact arrangement, with 72 contacts on three sides of the module, whereas the Agilent design uses a ball grid array. An extension of the original Infineon/ Gore MSA specifications enabled the Agilent ball-grid-array pad to fit inside the same perimeter using traces to extend the electrical connections.
"The [new] multisource agreement is essentially the Agilent design, which is the newest entry into the market space," observes Murray. "Agilent took a different route, made the module smaller, made a different interconnect. It appears as though Gore and Mitel at least are going to go in that direction. And it would make sense-it is a natural evolution of smaller packaging and ball-grid-array interfaces."
"It's based largely on the design that we are getting ready to push out into the marketplace," confirms Tom Fawcett, marketing manager of optical interconnects at Agilent (San Jose, CA). "Although it's not identical, there are some changes that we will make in the second generation of the product." Agilent's new product released last month, the parallel optics P2500 module, features a ball grid array and an MTP/MPO connector.
"In parallel optics, one of the traditional problems has been availability of parts, so what we've done is we've taken a step in the direction of easing the OEM's mind in terms of availability," says Fawcett. "A good reference for this would be the two other multisource agreements that have been put in place that really serve as almost a de facto standard for what small-form-factor pluggable and small-form-factor pin-through-mold transceiver modules com ply to. The essence of it is that we have defined a footprint that allows customers to operate from 1 to 2.5 Gbits and has three interchangeable sources and the option of true surface-mount and what we call land grid array, which is a mechanical attachment to board, not solder-based but more connector-based. So it is a wide-scope agreement that is going to allow customers three good options," asserts Fawcett.
Following are the features defined by the new Twelve-Channel 2.5G Working Group Phase 1 Specification, found on all three participating companies' Websites:
- 12-channel parallel fiber modules.
- Separate transmitter and receiver modules.
- 1- to 2.7-Gbaud (per channel) signal rate (accommodates 2.488 Gbits/sec with forward error correction).
- Data I/O is CML-compatible with DC blocking capacitors.
- Link lengths up to 220 m with 50/125-micron, 500-MHz-km multimode fiber.
- Channel bit error rate of 10-12.
- Standard MTP (MPO) ribbon-fiber connector interface.
- Connectivity options-ball grid array for solder assembly, land grid array for non-solder assembly.
Agilent will offer a 12-channel parallel fiber-optic module that meets these MSA specifications in early 2002, according to Fawcett. "We would be working with the customer base to do all the necessary cutovers," he adds.
Mitel, in early production with its first parallel fiber-optic module this month, the 623 family of parallel fiber-optic modules, will offer modules that are complaint with the new MSA specifications by the end of the year. The 623 modules, shipping this month, are mechanically different from the specifications in the Infineon/Gore MSA, says a Mitel company spokesperson. Gore is also expected to offer a parallel fiber-optic module that is complaint with the new MSA by year-end.
Infineon is currently ramping up production of the parallel optic module PAROLI to support several customer designs worldwide, according to the company. The average monthly output tripled over the last six months and is targeted to increase further throughout this year. The current design is used in supercomputing and terabit router/switch applications.
"Infineon does not intend to join the recently announced MSA from Agilent/Mitel/Gore," says a company spokesperson. "Infineon is the leading supplier of 12-channel parallel optic modules with several years of production history for 12-channel modules with 840-nm VCSEL array/ribbon-fiber technology. The overall performance of the module, specifically in the areas of high data rate, low power consumption, and superior reliability, have not been matched by other companies in the market. As we announced in August of last year, a fully compatible drop-in second source was established when the technology was licensed to Molex in August; production is targeted for later this year."
"Infineon's not automatically out by any stretch," says Murray. "But this would appear to be a very good strategy for the three companies that haven't shipped such volumes yet."