ClockWorks™ Dual 10-Gigabit/Gigabit
Ethernet 62.5MHz, 125MHz, or 156.25MHz,
Ultra-Low Jitter LVCMOS Clock Frequency
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.
• Generates two LVCMOS outputs
• Operating supply modes:
− 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:
− 100KHz: −126dBc/Hz
• Temperature range: –40°C to +75°C
• Green-, RoHS-, and PFOS-compliant
• Available in 16-pin TSSOP
• 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 +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
firstname.lastname@example.org or (408) 955-1690