BURNABY, British Columbia The process-technology race for physical-layer devices at high Sonet rates is heating up with the new year. PMC-Sierra Inc. will expand its CMOS products with new spins of its popular Suni (Saturn user network interface) design, while Vitesse Semiconductor Inc. (Camarillo, Calif.) and Applied Microcircuits Corp. (AMCC; San Diego) launch GaAs and bipolar products, respectively, to handle a variety of transceiver and clock-generation duties.
PMC-Sierra will take Suni in two directions at the OC-12 (622-Mbit/second) Sonet line rate. The PM5356 SUNI-622-MAX pulls together Sonet framing and ATM cell processing, then adds serializer/deserializer, clock synthesis and clock recovery to the feature set. The PM5357 SUNI-622-POS, meanwhile, is optimized for packet-over-Sonet applications.
The MAX is the star of the show for integration, said Steve Perna, vice president of marketing for PMC-Sierra, based here. It includes an on-chip phase-locked loop that meets Bellcore GR 253 jitter specs, and integrates all functions between the optical transceiver and the Utopia system interface. It is the first device to meet the Utopia Level 3 spec, which supports native OC-12 and channelized OC-48 (2.5-Gbit/s) Sonet line rates. It is designed to interface directly with PMC's 7322 RCMP ATM cell processor, and with the PM73487 QRT switching chip set, which PMC acquired from Integrated Telecom Technology Inc.
In addition to integration, the 3.3-V CMOS chip sets averages 2 W in power dissipation, which will allow Sonet and wave-division mux systems to achieve new densities in line cards.
The PMC5357 POS device is intended more for specialized routers and access systems that will run Internet Protocol packets directly over Sonet, without an intervening ATM layer. Edge router startup Redstone Communications Inc. is among those using the POS device. Like the MAX device, the 5357 integrates serializer/deserializer, clock recovery and clock synthesis blocks, but adds support for direct IP mapping over Sonet, as specified by the Saturn POS Working Group. The 5357 in 304-pin BGA is $249 in 1,000-piece units, while the 5356 is $199 in a similar package.
Vitesse is aiming at the same mix of ATM and POS applications with its new Sonet transceivers, but emphasizing the integration of clock recovery and multiplication in the transceiver, rather than in the UNI device. The VSC8116 and VSC8117 are transceivers with an on-chip clock multiplication unit that supports both 155-Mbit and 622-Mbit operation. The VSC8117 includes a clock recovery unit as well as a clock multiplier.
An on-chip PLL can be selected for OC-3 or OC-12 rates. The devices support 8-bit serial/parallel and parallel/serial conversion, and include a variety of loopback and loop-timing modes for in-system test. The VSC8117, intended for designs where clock recovery is not included in the UNI device, uses an on-chip CRU block for demultiplexing.
Both transceivers are packaged in a special 64-pin plastic quad flatpack with integrated heat sink, priced at $33 for the VSC8116 and $35 for the VSC8117, in quantities of 100.
AMCC is offering two standalone clock and data-recovery devices for Sonet and ATM applications. The S3047 is an OC-48 (2.5-Gbits/s) device that does not require an external clock, and is intended for line-card applications directly supporting optical or WDM interfaces. The S3050 CDR is a device intended to support OC-3, OC-12, OC-48 and Gigabit Ethernet speeds, for systems requiring multiple-speed support.
Both new AMCC devices employ an on-chip PLL, but integrate different feature sets for handling either high speeds with no external clock, or multiple speeds in one system. The S3047 supports scrambled Non-Return-to-Zero data at 2.5-Gbit rates, while the S3050 supports NRZ data at a variety of line rates. Both clock chips include phase detector, loop filter and on-chip VCO. The devices use a small LLCC package that measures 7 mm2 for the S3047, and 9 mm2 for the S3050. Price in lots of 100 is $145 for the S3047, $165 for the S3050.