ADI’s AD9551 clock generator reduces cycle time and complexity in networking and communications systems.
Allows for efficient support of multiple networking and communications standards.
NORWOOD, Mass. Feb. 25 /PRNewswire-Asia/ -- Analog Devices, Inc. (ADI) (http://www.analog.com/ ), the world leader in data conversion technology, introduced today a clock generator that simplifies clock design and reduces the need for oscillators in multi-standard networking and communications infrastructure systems. The AD9551 clock generator (http://www.analog.com/pr/AD9551 ) features a new, simplified architecture engineered by ADI that can generate and translate multiple precision network clock frequencies, which enables the replacement of as many as five oscillators. Oscillators support forward error correction (FEC), holdover, switchover, and precise frequency generation-functions that are essential in network switches, routers, and line cards.
In addition to saving board space, the AD9551 provides more accurate and reliable performance than discrete oscillators, while reducing system development time and complexity by making it easier for networks relying on incompatible standards to share and transfer data.
The AD9551 clock generator (http://www.analog.com/pr/AD9551 ) accepts one or two reference input signals and generates one or two output signals that are harmonically related by a programmable factor of 1 to 63. Precisely translating the reference frequency to the desired output frequency, it includes input receivers and output drivers that are capable of either single-ended or differential operation. On-chip reference monitoring and switchover circuitry internally synchronize the two references to prevent phase perturbations at the output in the event of a reference failure.
Should either or both references fail, the AD9551 maintains a steady output signal with no phase disturbance on the output. The device relies on an external 26-MHz crystal (nominal) and the internal digitally-compensated crystal oscillator (DCXO) of the first of two cascaded fractional-N phase-locked loops (PLLs) to provide a clean reference for the second PLL, and to hold the output frequency in case of reference failure. The second fractional-N PLL enables fine precision output frequency tuning with low phase noise. The AD9551 provides a serial-peripheral interface (SPI) port, and pin-selectable pre-set divider values that offer an assortment of frequency ratios, including all the standard rates for Gigabit Ethernet (644.53125 MHz), 10 Gigabit Ethernet (625 MHz), SONET/SDH (622.08 MHz), and Fiberchannel (657.421875 MHz) as well as the established FEC ratios (15/14, 239/237, 239/238, 255/237, 255/238).
In addition to network clocks (http://www.analog.com/clocks-timing ), including the AD9520 (http://www.analog.com/en/ad9520/productSearch.html ), AD9522 (http://www.analog.com/en/ad9522/productSearch.html ), ADCLK905 (http://www.analog.com/ADCLK905 ), ADCLK907 (http://www.analog.com/ADCLK907 ) and ADCLK925 (http://www.analog.com/ADCLK925 ) Ultrafast SiGe ECL Clock/Data Buffers and the Ultrafast, SiGe, Open-Collector HVDS Clock/Data Buffer, ADI makes a wide range of components addressing all aspects of networking and communications system design, from power management to analog and mixed-signal solutions.
Availability and Pricing
Product Samples Availability Temperature Price Each Packaging
Range Per 1000
AD9551 Feb 2009 May 2009 -40C to +85C $14.75 40-lead LFCSP
About Analog Devices
Innovation, performance, and excellence are the cultural pillars on which Analog Devices has built one of the longest standing, highest growth companies within the technology sector. Acknowledged industry-wide as the world leader in data conversion and signal conditioning technology, Analog Devices serves over 60,000 customers, representing virtually all types of electronic equipment. Celebrating over 40 years as a leading global manufacturer of high-performance integrated circuits used in analog and digital signal processing applications, Analog Devices is headquartered in Norwood, Massachusetts, with design and manufacturing facilities throughout the world. Analog Devices’ common stock is listed on the New York Stock Exchange under the ticker “ADI” and is included in the S&P 500 Index. http://www.analog.com .
