SM844256 Datasheet, PDF (1/8 Pages) Micrel Semiconductor – 10 Gigabit Ethernet and SONET, 6 Output, Ultra-Low Jitter LVDS Frequency Synthesizer

SM844256
10 Gigabit Ethernet and SONET, 6 Output,
Ultra-Low Jitter LVDS Frequency
Synthesizer
General Description
The SM844256 provides a low-noise timing solution for
high speed, high accuracy synthesis of clock signals.
Common applications include SONET, Gigabit Ethernet,
10 Gigabit Ethernet, and similar networking standards. It
includes a power reduction methodology, along with a
patented RotaryWave^TM architecture that provides a very
stable clock with very low noise.
Power supplies of either 3.3V or 2.5V are supported, with
superior jitter and phase noise performance. The device
synthesizes different low noise LVDS output frequencies
such as 125MHz, 156.25MHz, 312.5MHz, and 625MHz for
Ethernet applications; 77.76MHz, 155.52MHz, 311.04MHz,
and 622.08MHz for SONET applications. The crystal
reference frequencies used include 25MHz and 19.44Mhz
for Ethernet and SONET applications, respectively.
The SM844256 is an excellent replacement for IDT Femto-
clocks, with improved accuracy, power consumption,
waveform integrity, and jitter.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• Generates six LVDS outputs
• 2.5V or 3.3V operating range
• Typical phase jitter @ 125MHz
(1.875MHz to 20MHz): 80 fs (typical) @ 3.3V
• 75MHz to 625MHz output frequencies
• Industrial temperature range
• Green, RoHS, and PFOS compliant
• Available in 24-pin TSSOP EPAD
• Operating supply modes:
Core/Output
3.3V/3.3V, 3.3V/2.5V, 2.5V/2.5V
Applications
• SONET
• Gigabit Ethernet
• 10-Gigabit Ethernet
• Infiniband
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Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
July 2010
M9999-072110-B