One of the newest modules to hit the market comes from Raltron Electronics Corp. The company's SY10 Stratum 3/3E synchronization module is a digital phase-locked loop (PLL) that addresses timing, jitter and wander in a single module. Designed for asynchronous transfer mode, Sonet, SDH and wireless systems, the timing solution complies with ITU-T recommendations G.812/G.813 and Telcordia (Bellcore) GR-1244-CORE for Stratum 3E and 3 applications.

The SY10 module communicates in real-time with the host system, which relieves the host system from gathering synchronous information, allowing it to make very fast and accurate decisions by pulling the information from the module, said Ronen Cohen, marketing director for high-end products at Raltron Electronics.

The unit supports three modes of operation: locked to references, holdover and free run. It accepts reference inputs from up to six independent sources from 8 kHz to 77.77 MHz and offers up to three outputs from 8 kHz to 77.76 MHz.

Software residing in the SY10 digital signal processor provides switching between reference inputs, real-time calculations of the filtering algorithms for jitter and wander as well as alarm, status, and messaging functions. Other key features include a host interface for configuring and remote monitoring, and phase buildout for the output clock. A JTAG interface allows the module to be reprogrammed with future versions of software without removing it from the system.

Raltron's Web site, at www.raltron.com, provides such helpful white papers as "Stratum Levels Defined" and "Designing Synchronization Sources in a Network Environment." It also has answers to frequently asked questions.

Connor-Winfield Corp. has also been quite active in this arena, with the launch of a Stratum 3E complete system clock module and an enhanced Stratum 3 timing module. The Stratum 3E clock module, the STM-S3E for timing cards, complies with GR-1244-CORE, GR-253-CORE and ITU-T-G.813. The module provides a backplane clock reference in time-division multiplex (TDM), plesiochronous digital hierarchy, Sonet and SDH network equipment.

The module offers output frequencies from 1.544 MHz to 38.88 MHz, a 12-parts-per-billion holdover across the full temperature range of 0 degrees C to 70 degrees C and free run of less than plus/minus 4.6 ppm. It also provides alarms for loss of reference (LOR), phase buildout and reference frequency limit.

The Connor-Winfield MS-TM-S3-TR Stratum 3 timing module features tristate capabilities and a power-on-reset function for power-up reliability. Designed for Sonet, TDM, SDH and PDH applications, the module features two synchronous outputs available from 8 kHz to 77.76 MHz and free-run and holdover modes of operation.

One of the newest features of synchronous timing modules is holdover, typically provided by software in the module, said Bob Dranter, marketing director for Connor-Winfield. This allows the module to detect when a signal has disappeared and notify the PLL circuit to hold the frequency or switch to a different frequency, he said. In next-generation products, customers are looking for more autonomous operation, said Ed Miguel, engineering manager for Connor-Winfield.

Year-end push

Vectron International is developing both timing modules and frequency translation devices. Five or six frequency translator products are planned by year's end. Most recently, Vectron introduced two products, the CS-300 clock smoother and FX-700 frequency translator, for line-card applications.

The surface-acoustic-wave-based clock smoother is used to clean up noisy input frequencies from 1.024 MHz to 700 MHz to provide an ultralow-jitter input signal. Offering excellent jitter performance and high output frequencies, the FX-700 comprises four devices in a single small package size.

For timing card applications, Vectron has released its DDS-based TM-055 Stratum 3 timing synchronization modules, which feature input frequencies from 8 kHz to 155.52 MHz and output frequencies up to 155.52 MHz. They're available with a 3.3-Vdc or 5-Vdc supply and with or without phase buildout. The device measures 2 x 2 x .585 inch.

Champion Technologies also offers a Stratum 3 synchronization module that meets Telcordia GR-1244-CORE requirements. Champion's timing and synchronization platforms are available with a variety of features that can be modified to fit a customer's needs. For example, output frequencies for T1, E1, OC and STM applications are available, including 16.384 MHz, 19.44 MHz and 38.88 MHz, the company said.

Key features of Champion's CTM5100A module are customizable alarm output options, forced free-run and holdover functions and automatic free run upon an LOR alarm condition.

Two new players, M-tron Industries Inc. and SaRonix, are sampling product for specific customers. M-tron is sampling one customer-specific module and has five other products in development. Samples will be available in one to two months, with a product launch planned in four to five months.

SaRonix is also starting to introduce products that range from simple PLL solutions to more complex frequency translators and true timing modules. The company is marketing some general capabilities for its STM series of timing modules and SFT100 frequency translators which are 25 to 33 percent smaller than what's available.

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Company Contacts

Champion Technologies Inc.
(847) 451-1000
www.champtech.com
EETInfo No. 604

Connor-Winfield Corp.
(630) 851-4722
www.conwin.com
EETInfo No. 605

M-tron Industries Inc.
(605) 665-9321
www.mtron.com
EETInfo No. 606

Raltron Electronics Corp.
(305) 593-6033
www.raltron.com
EETInfo No. 607

Vectron International
(203) 853-4433
www.vectron.com
EETInfo No. 608

SaRonix
(650) 470-7700
www.saronix.com
EETInfo No. 609