Electronic Design

Oscillators And Timing Devices

VCXOs Target Sonet/SDH Telecommunications Equipment
C-MAC MicroTechnology
+44 (9) 1279 824200; fax +44 (0) 1279 82486; www.cmac.com

The CFPV-5 high-frequency SMT voltage-controlled crystal oscillators (VCXOs) offer high frequency stability and low jitter. These devices are designed for use in Sonet/SDH telecommunications equipment and proposed 10-Gbit/s Ethernet applications. The CFPV-5 offers standard nominal output frequencies of 622.0800, 666.5143, and 725.104 MHz. Custom frequencies can be specified between 550 and 750 MHz.

CFPV-5 devices select and amplify a harmonic of a lower-frequency bulk acoustic wave (BAW) quartz crystal oscillator to achieve their nominal frequencies. Phase noise at 10 kHz offset is below −125 dBc/Hz. The devices feature a temperature stability of ±20 ppm over the temperature range from −5°C to 70°C. According to the company, low jitter and phase noise specifications make the CFPV-5 suitable for high-capacity transmission equipment. End users can multiply the nominal output to support data rates of up to 10 Gbits/s. Applications include multiplexing/demultiplexing, fiber transmission, and frequency translation equipment. The CFPV-5 comes in a FR4-based surface-mount package measuring 30.6 by 26 by 5.3 mm. Tape-and-reel format is also available. For pricing and availability information, contact the company.

Oscillators Suit Prototype
Development, Product Manufacturing

Raltron Electronics Corp.
(305) 593-6033; fax (305) 594-3973; www.raltron.com

Members of a family of programmable clock oscillators function for prototype development and product manufacturing. Model CP2 operates up to 200 MHz on 5 V. Also, it uses only 50 mA. Model CP4 operates at 100 MHz on 3.3 V. This model draws only 30 mA. Both devices offer ±20-, ±50-, or ±100-ppm stability. They feature an output enable/disable function for use in per-channel multiplexers and other applications that require the output to be switched off at high Z.

Both the CP2 and the CP4 are housed in 70-mm3 ceramic packages. They produce any arbitrary frequency between 1 and 200 MHz. Output levels are specified at 0.5 to 4.5 V for the CP2 oscillator. The CP4 oscillator is specified for output levels of 0.33 to 2.97 V. Rise and fall times are 4 ns each. Two duty-cycle selections are available, including 40% to 60% (normal) and 45% to 55% (tight). Both of the oscillators are capable of driving 15-pf loads. Available operating-temperature ranges include 0°C to 70°C and −40° to 85°C. The storage-temperature range is −55°C to 125°C. In 50- to 500-unit quantities, the CP2 and CP4 oscillators are priced at $5.00 each or less, except for the ±20-ppm units.

System Clock Module Fits Timing Card Applications
Connor-Winfield Corp.
(630) 851-4722; fax (630) 851-5040; www.conwin.com

The STM-S3E is a complete system clock module for Stratum 3E timing card applications. It functions in accordance with GR-1244-CORE, GR-253-CORE, and ITU-T-G813. This module provides a reliable backplane clock reference to line cards for use in TDM, PDH, Sonet, and SDH network equipment. According to the company, this module is the only product of its kind to completely conform to the strict requirements of Telecordia's GR-1244-CORE standard for Stratum 3E clocks.

The footprint of the STM-S3E is the same as the existing STM-33 and STM-33+ modules. This compatibility enables easy integration into existing circuits. Output frequencies for this module range from 1.544 to 38.88 MHz. It enables 5- or 3.3-V operation. Alarms for LOR, LOL, Phase Build Out, and Reference Frequency Limit are incorporated into this device. A 1-MHz jitter/wander filter is also included. The STM-S3E module is now available. In 1000-unit quantities, it costs $680.

Off-The-Shelf Crystal Oscillator Series Features Chip-Set Option
Fox Electronics
(888) GET-2-FOX; fax (941) 693-1554; www.foxonline.com

A standard off-the-shelf crystal oscillator series features a new option designed specifically for use with Intersil's PRISM 2.5 and 3.0 11-Mbit/s chip sets. The F4106-440/1.4PRISM complements the PRISM chip sets for wireless connectivity applications, including home computers, laptops, palmtops, PDAs, and digital cameras. This oscillator is offered in the industry-standard 5- by 7-mm ceramic SMD package. It delivers a stable ±25 ppm. According to the company, this oscillator features extremely low jitter at special PRISM circuit voltages.

This device features a standard operating-temperature range of −10°C to 70°C. Featuring an extremely low profile, it offers a frequency of 44 MHz. Optional features available on special order include an extended temperature range of −40° to 85°C. A 22.0-MHz version is available for the PRISM 1. In 1000-unit quantities, the F4106-440/1.4PRISM costs $4.00 each.

VCO Delivers Unmatched Noise Performance For SDH Radios
Z-Communications Inc.
(858) 621-2700; fax (858) 621-2722; www.zcomm.com

The CLV1015E is a voltage-controlled oscillator (VCO) for SDH microwave radio systems. According to the company, this device utilizes patented design techniques to deliver unequalled SSB phase noise performance in an inexpensive and compact SMT package. It generates frequencies between 995 and 1032 MHz with 0.6 to 5.0 V dc of control voltage. It tunes the 37-MHz bandwidth with an average sensitivity of 16 MHz/V. It exhibits a clean spectral signal of −112 dBc/Hz typically. The device operates from a 4.5-V dc supply and draws only 10 mA.

According to the company, this VCO enables quick implementation into PLLs where the error voltage can be taken directly from the IC's charge pump circuitry. This rugged oscillator delivers −0.5±3.5 dBm into a 50-Ω load. It is designed to operate over the extended commercial-temperature range of −5°C to 85°C. It comes in the industry-standard MINI surface-mount package measuring 0.50 by 0.50 by 0.22 in. According to the company, it is ideal for automated surface-mount assembly and reflow. The CLV1015E costs $15.95/VCO for prototyping.

SMD VCXO Eliminates Need For Rail-To-Rail System Components
MF Electronics
(914) 712-2200; fax (914) 576-6204; www.mfelectronics.com

The 5-V R3206 voltage-controlled crystal oscillator (VCXO) provides wide ±100-ppm capture with a narrow 0.5- to 4.5-V pull voltage. According to the company, this device eliminates the need for rail-to-rail system components. Maximum deviation is ±200 ppm. This constrains the voltage-to-frequency curve to a near straight line. This tight F/V linearity simplifies the design of phase-locked-loop (PLL) data-cleanup circuits.

This surface-mount VCXO is available with center frequencies (at 2.5 V) from 3 to 55 MHz. The VCXOs also guarantee advanced jitter, linearity, and tristate specifications. Center-frequency stability is ±50 ppm from 0°C to 70°C under all load and supply-voltage conditions. Waveform symmetry is better than 45/55. While the rise time is 2 ns, the typical jitter is 8 ps. These VCXOs run on nominal 5-V dc supplies. The oscillators are available on tape-and-reel for automated parts handling. The oscillators' rugged six-pad gold/ceramic design withstands rigorous high-speed pc-board assembly. In OEM quantities, the R3206 VCXOs cost less than $6 each.

Synchronous Timing Modules Target
Wireless Communications Applications

MTI-Milliren Technologies Inc.
(978) 465-6064; fax (978) 465-6637; www.mti-milliren.com

A Stratum III and IIIe Synchronous Timing Module comes standard with five user-programmable input reference frequencies from 8 kHz to 311.04 MHz. Any multiple of 8 kHz from 24 kHz to 100 MHz can be supported. Five user-selectable output reference frequencies from 2 kHz to 311.04 MHz support 20 industry-standard telecommunications frequencies.

Additional features include a redundant master-slave configuration and full compliance with Bellcore GR-1244-CORE-STR 3E and ITU: G.812 Type III standards. The module supports free-running, locked, and holdover modes of operation while filtering jitter from the incoming signals. Output-signal levels include TTL, ACMOS, LVDS, and LVPECL. According to the company, this module is suited for a wide range of applications, including Sonet and SDH transport equipment, network synchronization, cellular and WLL base stations, core IP routers and switches, and ATM wireless communications systems. For pricing and availability information, contact the company.

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