SM840002 Datasheet, PDF (1/9 Pages) Micrel Semiconductor – ClockWorks™ Dual 10-Gigabit/Gigabit Ethernet 62.5MHz, 125MHz, or 156.25MHz

SM840002
ClockWorks™ Dual 10-Gigabit/Gigabit
Ethernet 62.5MHz, 125MHz, or 156.25MHz,
Ultra-Low Jitter LVCMOS Clock Frequency
Synthesizer
General Description
The SM840002 is a dual 10-Gigabit Ethernet and Gigabit
Ethernet, 62.5MHz, 125MHz, or 156.25MHz LVCMOS
clock frequency synthesizer and a member of the
ClockWorks™ family of devices from Micrel. It provides a
low-noise timing solution for high-speed, high-accuracy
synthesis of clock signals. It includes a patented
RotaryWave^® architecture that provides a very stable clock
with very-low noise.
Power supplies of either 2.5V or 3.3V are supported, with
superior jitter and phase-noise performance. The device
synthesizes a 62.5MHz, 125MHz, or 156.25MHz, low-
noise LVCMOS output pair for Ethernet applications. The
crystal reference frequency is 25MHz.
The SM840002 is an excellent replacement for IDT
FemtoClocks^®, with improved waveform integrity, and jitter.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• Generates two LVCMOS outputs
• Operating supply modes:
− Core/Output
− 3.3V/3.3V, 2.5V/2.5V
• Typical phase jitter @156.25MHz~64 fs
(1.875MHz − 20MHz)
• Crystal frequency: 25MHz
• 62.5MHz, 125MHz, or 156.25MHz output frequency
• Output Skew: 12ps (maximum)
• Phase Noise @ 156.25MHz:
− 1KHz:
−126dBc/Hz
− 10KHz:
−130dBc/Hz
− 100KHz: −126dBc/Hz
− 1MHz:
−139dBc/Hz
− 10MHz:
−165dBc/Hz
− 20MHz:
−166/dBc/Hz
• Temperature range: –40°C to +75°C
• Green-, RoHS-, and PFOS-compliant
• Available in 16-pin TSSOP
Applications
• Gigabit Ethernet
• 10-Gigabit Ethernet
ClockWorks is a trademark of Micrel, Inc.
RotaryWave is a registered trademark of Multigig, Inc.
FemtoClocks is a registered trademark of IDT, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
November 2010
M9999-110810-A
[e-mail] or [phone]