SM802121 ClockWorks 10GbE (156.25MHz), Ultra-Low Jitter, LVPECL Frequency Synthesizer General Description Features The SM802121 is a member of the ClockWorks family of Generates one LVPECL clock outputs at 156.25MHz devices from Micrel and provides an extremely low-noise 2.5V or 3.3V operating range timing solution for 10GbE Ethernet clock signals. It is Typical phase jitter 156.25MHz based upon a unique patented RotaryWave architecture (1.875MHz to 20MHz): 110fs that provides very-low phase noise. Industrial temperature range The device operates from a 2.5V or 3.3V power supply Green, RoHS-, and PFOS- compliant and synthesizes an LVPECL output clock at 156.25MHz. The SM802121 accepts a 25MHz crystal or LVCMOS Available in 24-pin 4mm 4mm QFN package reference clock. Data sheets and support documentation can be found on Applications Micrels web site at: www.micrel.com. 10 Gigabit Ethernet Block Diagram ClockWorks is a trademark of Micrel, Inc RotaryWave is a registered trademark of Multigig, Inc. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. SM802121 (1) Ordering Information Part Number Marking Shipping Temperature Range Package SM802121UMG 802121 Tube 40C to +85C 24-Pin QFN SM802121UMGTR 802121 Tape and Reel 24-Pin QFN 40C to +85C Note: 1. Devices are Green, RoHS-, and PFOS- compliant. Pin Configuration 24-Pin QFN (Top View) January 2012 M9999-011212-A 2 hbwhelp micrel.com or (408) 955-1690