Silicon Laboratories SI5351A/B/C - Manual

Preliminary Rev. 0.95 8/11 Copyright © 2011 by Silicon Laboratories Si5351A/B/C
This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
S i 5 3 5 1 A / B / C
I
2
C - P
R O G R A M M A B L E
A
N Y
- F
R E Q U E N C Y
C M O S C
L O C K
G
E N E R A T O R
+ V C X O
Features
Applications
Description
The Si5351 is an I
2
C configurable clock generator that is ideally suited for replacing
crystals, crystal oscillators, VCXOs, phase-locked loops (PLLs), and fanout buffers in
cost-sensitive applications. Based on a PLL/VCXO + high resolution MultiSynth fractional
divider architecture, the Si5351 can generate any frequency up to 160 MHz on each of its
outputs with 0 ppm error. Three versions of the Si5351 are available to meet a wide
variety of applications. The Si5351A generates up to 8 free-running clocks using an
internal oscillator for replacing crystals and crystal oscillators. The Si5351B adds an
internal VCXO and provides the flexibility to replace both free-running clocks and
synchronous clocks. The Si5351B eliminates the need for higher cost, custom pullable
crystals while providing reliable operation over a wide tuning range. The Si5351C offers
the same flexibility but synchronizes to an external reference clock (CLKIN).
Functional Block Diagram
 Generates up to 8 non-integer-related
frequencies from 8 kHz to 160 MHz
 I
2
C user definable configuration
 Exact frequency synthesis at each output
(0 ppm error)
 Highly linear VCXO
 Optional clock input (CLKIN)
 Low output period jitter: 100 ps pp
 Configurable spread spectrum selectable
at each output
 Operates from a low-cost, fixed frequency
crystal: 25 or 27 MHz
 Supports static phase offset
 Programmable rise/fall time control
 Glitchless frequency changes
 Separate voltage supply pins:
 Core VDD: 2.5 or 3.3 V
 Output VDDO: 1.8, 2.5, or 3.3 V
 Excellent PSRR eliminates external
power supply filtering
 Very low power consumption
 Adjustable output-output delay
 Available in 3 packages types:
 10-MSOP: 3 outputs
 24-QSOP: 8 outputs
 20-QFN (4x4 mm): 8 outputs
 PCIE Gen 1 compliant
 Supports HCSL compatible swing
 HDTV, DVD/Blu-ray, set-top box
 Audio/video equipment, gaming
 Printers, scanners, projectors
 Residential gateways
 Networking/communication
 Servers, storage
 XO replacement
Si5351A
Multi
Synth
N
N = 2 or 7
I 2 C
SSEN
OEB
Multi
Synth
0
Multi
Synth
1
Si5351B
PLL
VC VCXO
I 2 C
SSEN
OEB
Multi
Synth
0
Multi
Synth
1
Multi
Synth
2
Multi
Synth
3
Multi
Synth
4
Multi
Synth
5
Multi
Synth
6
Multi
Synth
7
Si5351C
PLLA
CLKIN
PLLB
I 2 C
INTR
OEB
Multi
Synth
0
Multi
Synth
1
Multi
Synth
2
Multi
Synth
3
Multi
Synth
4
Multi
Synth
5
Multi
Synth
6
Multi
Synth
7
XA
XB
OSC
XA
XB
OSC
PLLB
PLLA XA
XB
OSC
Ordering Information:
See page 66
10-MSOP
24-QSOP
20-QFN