Crystal Oscillators suit TDM switching systems.
Press Release Summary:
Series CFPT-9400 TCVCXOs achieve jitter performance of less than 3 ps rms, 10 Hz to 80 MHz by utilizing high frequency fundamental crystal and harmonic multiplication. Incorporation of Pluto temperature compensation technology keeps frequency stability to ±1.5 ppm over 0-80ºC temperature range. Units offer output frequencies of 622.08000, 666.51436, and 669.32658 MHz for SDH/SONET switches, and 644.53125 and 693.48299 MHz for Gigabit Ethernet applications.
Original Press Release:
Ultra High-Frequency TCVCXOs Boost Efficiency of SDH/SONET and Gigabit Ethernet Optical Networks
First ±1.5 ppm TCVCXOs at 622 MHz and above
Durham, NC, May 2005 - C-MAC MicroTechnology has launched a range of low-jitter high-frequency TCVCXOs (temperature compensated, voltage controlled crystal oscillators) for use in TDM (time division multiplexing) switching systems for optical fiber backbone infrastructure. By using a high-frequency fundamental crystal together with C-MAC's Pluto temperature compensation technology, the new CFPT-9400 range is designed to eliminate reception 'slips' that compromise the effective bandwidth of SDH/SONET and Gigabit Ethernet fiber networks.
As telecoms carriers increase data rates across their long-haul fiber infrastructure, it becomes more sensitive to short-term frequency discrepancies between transmitting and receiving equipment, causing faulty reception of data packets. These discrepancies can be caused by jitter in the signal or by rapid fluctuations in ambient temperature at either end of the fiber.
Improving the jitter performance and temperature stability of the oscillators increases the effective capacity of the fiber network by reducing the number of dropped packets and hence the number of resends required, and so increases the effective capacity of the fiber network.
The CFPT-9400 achieves excellent jitter performance of less than 3 ps rms 10 Hz to 80 MHz by avoiding the use of a phase locked loop in favour of a low-phase-noise HFF (high-frequency fundamental) crystal and harmonic multiplication. The HFF crystal is coupled through a SAW (surface acoustic wave) filter, suppressing any sub-harmonics of the operating frequency to typically less than -55 dBc.
The incorporation of Pluto temperature compensation technology keeps frequency stability over the 0º to +80ºC operating temperature range to ±1.5 ppm. Besides eliminating temperature-related slips, this allows the CFPT-9400 to keep well within the Telcordia specification of ±20 ppm all-causes stability over a 20-year lifetime. Because Pluto technology uses an analogue temperature compensation technique, it exhibits superior phase noise characteristics, eliminating another potential source of jitter.
The CFPT-9400 is available in five output frequencies: 622.08000 MHz, 666.51436 MHz and 669.32658 MHz for SDH/SONET switches with or without FEC (forward error correction); and 644.53125 MHz and 693.48299 MHz for Gigabit Ethernet and emerging 10 Gbit Ethernet applications, with or without FEC. Frequency adjustment of up to ±60 ppm is available through external voltage control.
Supply voltage is 3.3 V with a low current consumption of 65 mA typical, and output is 3.3 V PECL (LVPECL) compatible. The CFPT-9400 is packaged as an industry standard 14 x 9 mm SMD. It is designed for lead free soldering and compliant with all requirements of the RoHS regulations.
Geoff Trudgen, Senior Design Engineer with C-MAC Frequency Products, commented: "Short-term frequency stability is a hugely important factor in long-haul fiber networks, and will become ever more so as carriers move from today's SDH/SONET and Gigabit Ethernet technology to 10 Gbit/s and beyond. Use of Pluto temperature compensation technology in a low-jitter HFF-based oscillator gives us stability to within ±1.5 ppm over temperature range - far better than has previously been possible at such high frequencies - allowing the CFPT-9400 to fulfill the requirements of TDM fiber backbone switches in an efficient and cost effective manner."
About C-MAC MicroTechnology:
C-MAC MicroTechnology specializes in the design and manufacture of high-reliability products. With design and manufacturing facilities in the UK, France, Belgium and Canada and additional dedicated sales offices within Europe, the USA and China, C-MAC MicroTechnology serves the military, aerospace, transportation, medical, industrial and communications equipment sectors, and has built up an extensive portfolio of intellectual property resources and an impressive electronics design and manufacturing pedigree geared specifically to these industries. C-MAC's products are usually found in applications that operate in harsh environments, often at extremes of temperature or frequency. C-MAC MicroTechnology comprises two business units: C-MAC MicroSystems Solutions and C-MAC Frequency Products.
C-MAC Frequency Products has a 70-year history of manufacturing quartz-based frequency control products and now has four design, engineering, manufacturing and sales centers in Crewkerne, Harlow and Lincoln, UK, and Argenteuil, France. Its product range encompasses AT and SC cut crystals, crystal oscillators, voltage controlled crystal oscillators (VCXOs), temperature compensated crystal oscillators (TCXOs), oven controlled crystal oscillators (OCXOs), and rubidium oscillators and clocks. Particular specializations include patented ASIC-based high-stability TCXOs, ultrastable OCXOs and SDH/SONET reference oscillators.
C-MAC's proprietary temperature compensation technology, known as Pluto, provides digitally controlled analogue temperature compensation of output frequency to a high degree of accuracy, by applying four orders of Chebyshev polynomials to the signal. Depending on output frequency, it allows TCXOs with stability of better than ±0.3 ppm (parts per million) over their operating temperature range to be implemented within a standard 7 mm x 5 mm ceramic package.
Further information:
Jan Ooijman, C-MAC MicroTechnology. Tel: +44 (0)1279 774465. Fax: +44 (0)1279 774488. Email: marketing@cmac.com
