>VTSS is a good solid company who has the lion's share of OC48 and OC12 frontend circuit design wins with the likes of CSCO, LU, and Ascend.
this EET piece may interest you.
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Electronic Engineering Times
March 08, 1999, Issue: 1051
Section: Semiconductors
Sonet vendors innovate at chip and module levels
Loring Wirbel
San Diego - There was no shortage of analog front ends, including commodity single-chip transceivers for OC-48 (2.5-Gbit/second), at the Optical Fibers Conference show here. Even early commercial implementations of OC-192 (10-Gbit) transceivers were in evidence-both the interface circuits for 10-Gbit mux/demux and scrambling and the integrated modules that combine drivers and amps with a laser source.
And even as developers are pushing silicon processes toward 10-Gbit performance, the major players in both III-V materials and silicon are working to reduce the manufacturing costs and end prices of 2.5-Gbit parts. That means using CMOS where possible and plastic packages in almost all cases.
Most interface specialists addressed both markets simultaneously. Vitesse Semiconductor Corp. (Camarillo, Calif.), for example, rolled out a 2.5-Gbit/s limiting amp, a move that brings them closer to the optoelectronic interface. The company also introduced a mux/demux chip set for 10-Gbit networks.
Vitesse's strategy is to add full analog front-end capabilities for OC-48 and OC-192 networks with its new VSC7958 limiting amp. The 5-V GaAs IC integrates offset-correction circuitry and achieves a typical noise spec of 160 microvoltsrms. The $95 chip is packaged in a 16-pin glass wall flatpack.
Vitesse's mux/demux set, VSC8073 and VSC8074, will be offered at a production two-chip price of $500 per set, the price point for 10-Gbit parts that Vitesse said will be necessary even in early implementations. The 8073/8074 is a 16-bit mux interface design.
TriQuint Semiconductor Inc. (Hillsboro, Ore.) also pushed OC-48 products, sampling a multiplexer with integrated clock synthesis. The first of TriQuint's OC-48 product series, the TQ8213, is a 32:1 multiplexer that integrates a 75-mA output driver with the phase-locked loop-based synthesis.
Output options
The output from the TQ8213 can drive either an external optical modulator, a 50-ohm transmission line or a directly modulated laser. The TQ8223 is a companion demultiplexer. TriQuint said it plans to volume price the chips at $107.20 for the TQ8213 and $119.10 for the TQ8223.
Giga Inc., meanwhile, showed off early prototypes of its 16555A, a transmitter/muxer for 10-Gbit applications. Giga's vice president of North American marketing, Bill Woodruff, said his company's use of a special bipolar process from Siemens will allow fabrication of OC-192 parts that are cost-effective for many WAN applications.
Newcomers also are winning attention from customers for high-performance mux/demux products. At four-year-old Multilink Technology Corp. (Santa Monica, Calif.), for example, Richard Nottenburg, president and co-founder, pledged that his company would be process-neutral, evaluating a variety of BiCMOS, silicon germanium and III-V options for implementing interfaces with speeds of 10 Gbits or higher.
Multilink used the show to introduce a 16-bit mux/demux pair, the MTC1203 and MTC1204, as the first offerings in a line of Sonet analog products the company will produce.
Multilink said its next goal is offering on-chip Q-Factor measurement in an upcoming dedicated device. Q-Factor analysis is a bit-error-rate estimator that can be used on linear-channel systems, including those in use, without disturbing data.
Multilink will offer the Q-Factor Chip, which reads in a post-optical-receive analog signal and samples various thresholds and clock phases. The data then is sent to a microprocessor programmed with software algorithms implementing double-stress noise algorithms, which Multilink also provides.
Although the laser remains the most expensive item in the optical interface, the distributed-feedback (DFB) lasers used in higher-wavelength single-mode applications are showing volume price reductions similar to those for lower-end Fabry-Perot lasers.
Lots of companies used OFC as a venue to promote products using laser integration with silicon in hybrid modules.
On the transceiver module front, Ortel Corp. (Alhambra, Calif.) quietly showcased early samples of a 10-Gbit/s receiver, based on an integrated positive-intrinsic negative diode and GaAs PHEMT preamp. The 2860A has a sensitivity of -20 dBm and transimpedance of 1,200 ohms. John Rinks, vice president of marketing for telecom and satcom, said booth traffic suggested that Ortel was the only company promising near-term dates for volume shipments of 10-Gbit laser modules.
Mitsubishi Electronics America covered all Sonet line-rate bases at OFC, rolling out an integrated transceiver module at OC-3 (155 Mbits); an OC-48 distributed-feedback laser diode; and at OC-192, a distributed fiber laser diode and transmitter/receiver pair.
The transmitter/receiver pair for 10-Gbit networks relies on a transmitter with cooled DFB laser diodes, along with a driver IC; and a receiver based on a preamp and dedicated ICs for reshaping, retiming and regenerating an optical signal.
High integration in such markets still carries a high price tag: the MF-10KDS-T12 transmit device is priced at $18,500 in lots of 100, while the receive unit sells for $8,000.
Prices for DFB laser diodes for 10-Gbit networks are beginning to drop, however-$5,050 for standard FU-641 SEA modules with built-in optoisolator and $2,500 for the FU-632SEA long-haul and undersea modules. The price for Mitsubishi's OC-3 transceiver, in a 20-pin dual-in-line package, is dropping as well, carrying a $405 price tag in lots of 100.
Meanwhile, Lucent Technologies Inc.'s Microelectronics Division is going for a high degree of integration in its OC-48 transponder modules, which house up to 15 separate ICs in a 3.5 x 2.5-inch device. Although the TransLight transponders won't be sampling or have fixed prices until summer, Lucent exhibited two prototypes at OFC-a version that bundles mux/demux functions along with transmit/receive, and a version that integrates wavelength conversion for DWDM applications. Both devices will include all clock and data-recovery functions along with the 2.5-Gbit transmit and receive circuits, and will communicate directly to Lucent's Sonet transmission chips.
Meanwhile, Bookham Technology Ltd. (Oxfordshire, England) displayed some of the first bidirectional integrated modules for OC-3 Sonet line-extender applications. The BKM-3400 dual-wavelength trans- ceiver, intended for both 1,550- and 1,310-nm applications, integrates full automatic gain control transimpedance amp functions into the 2 x 9 package. |
