SM803XXX
Flexible Ultra-Low Jitter Clock Synthesizer
Clockworks™
FLEX2
General Description
The SM803xxx is a dual-PLL clock generator that achieves
ultra-low phase jitter (75fs RMS). With 12 total outputs and
dividers on each output, this device can generate 12
different frequencies up to 850MHz, from a low-cost quartz
crystal or a reference clock input.
Each of 12 outputs can be independently programmed to
LVPECL, LVDS, HCSL, or LVCMOS logic. For LVCMOS,
only the true side of the channel is used.
The SM803xxx is packaged in a 48-pin QFN with up to 10
outputs, or 84-pin QFN with 12 outputs.
Datasheets and support documentation are available on
Micrel’s web site at:
www.micrel.com.
Features
•
Generates up to 12 differential or single-ended
frequencies
•
75fs phase jitter @ 156.25MHz (1.875MHz to 20MHz)
•
180fs phase jitter @ 156.25MHz (12kHz to 20MHz)
•
On-chip power supply regulation for excellent power
supply noise immunity
•
Two high-performance PLL synthesizers to generate
multiple frequencies
•
Independently programmable output logic and
frequency:
−
Output logic: LVPECL, LVDS, HCSL, LVCMOS
•
Selectable input:
−
Crystal: 12MHz to 50MHz
−
Reference input: 12MHz to 850MHz
•
SPI programmable (see FLEX SPI documentation)
•
No external crystal oscillator capacitors required
•
2.5V or 3.3V operating power supply
•
Separate output power supplies:
−
Each bank can be at different power supply voltage
levels (4 banks of 3 outputs each)
•
Feedback input pins for use as zero delay buffer
•
Industrial temperature range,
−40°C
to +85°C
•
Green, RoHS, and PFOS compliant QFN packages:
−
84-pin, 7mm × 7mm (12 Diff. or Single ended outputs)
−
48-pin 7mm × 7mm (10 Diff. or Single ended outputs)
Block Diagram
Applications
•
•
•
•
•
•
•
1/10/40/100 Gigabit Ethernet – (GbE)
SONET/SDH
PCI-Express
CPRI/OBSAI – Wireless base station
Fibre Channel
SAS/SATA
DIMM (DDR2/DDR3/AMB)
Clockworks and Ripple Blocker are trademarks of Micrel, 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
July 26, 2013
Revision 1.0
hbwhelp@micrel.com
or (408) 955-1690
单片机
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
