SM844256

10 Gigabit Ethernet and SONET, 6 Output,

Ultra-Low Jitter LVDS Frequency

Synthesizer

July 2010

M9999-072110-B

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

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

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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