ACS8520T Semtech, ACS8520T Datasheet - Page 2
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ACS8520T
Manufacturer Part Number
ACS8520T
Description
Synchronous Equipment Timing Source (SETS) for Stratum 3/4E/4 and SMC Systems
Manufacturer
Semtech
Datasheet
1.ACS8520T.pdf
(150 pages)
Section
Description ................................................................................................................................................................................................. 1
Block Diagram............................................................................................................................................................................................ 1
Features ..................................................................................................................................................................................................... 1
Table of Contents ...................................................................................................................................................................................... 2
Pin Diagram ............................................................................................................................................................................................... 4
Pin Description........................................................................................................................................................................................... 5
Introduction................................................................................................................................................................................................ 8
General Description................................................................................................................................................................................... 8
Revision 3.02/October 2005 © Semtech Corp.
Table of Contents
ADVANCED COMMUNICATIONS
Overview .............................................................................................................................................................................................8
Input Reference Clock Ports .......................................................................................................................................................... 10
Clock Quality Monitoring................................................................................................................................................................. 12
Selection of Input Reference Clock Source................................................................................................................................... 14
Modes of Operation ........................................................................................................................................................................ 16
DPLL Architecture and Configuration ............................................................................................................................................ 19
Configuration for Redundancy Protection ..................................................................................................................................... 29
Output Clock Ports .......................................................................................................................................................................... 32
Locking Frequency Modes .................................................................................................................................................... 10
PECL/LVDS/AMI Input Port Selection .................................................................................................................................. 11
Activity Monitoring ................................................................................................................................................................. 12
Frequency Monitoring ........................................................................................................................................................... 14
Forced Control Selection....................................................................................................................................................... 15
Automatic Control Selection ................................................................................................................................................. 15
Ultra Fast Switching .............................................................................................................................................................. 15
Fast External Switching Mode-SCRSW Pin .......................................................................................................................... 15
Output Clock Phase Continuity on Source Switchover ....................................................................................................... 16
Free-run Mode ....................................................................................................................................................................... 16
Pre-locked Mode ................................................................................................................................................................... 16
Locked Mode ......................................................................................................................................................................... 16
Lost-phase Mode................................................................................................................................................................... 17
Holdover Mode ...................................................................................................................................................................... 17
Pre-locked2 Mode ................................................................................................................................................................. 19
TO DPLL Main Features ........................................................................................................................................................ 20
T4 DPLL Main Features ........................................................................................................................................................ 20
TO DPLL Automatic Bandwidth Controls.............................................................................................................................. 20
Phase Detectors .................................................................................................................................................................... 21
Phase Lock/Loss Detection.................................................................................................................................................. 21
Damping Factor Programmability......................................................................................................................................... 21
Local Oscillator Clock ............................................................................................................................................................ 22
Output Wander ...................................................................................................................................................................... 23
Jitter and Wander Transfer ................................................................................................................................................... 25
Phase Build-out ..................................................................................................................................................................... 25
Input to Output Phase Adjustment....................................................................................................................................... 26
Input Wander and Jitter Tolerance....................................................................................................................................... 26
Using the DPLLs for Accurate Frequency and Phase Reporting ........................................................................................ 28
Alignment of Priority Tables in Master and Slave ACS8520 .............................................................................................. 30
T4 Generation in Master and Slave ACS8520 .................................................................................................................... 30
Alignment of the Output Clock Phases in Master and Slave ACS8520............................................................................. 30
MFrSync and FrSync Alignment-SYNC2K............................................................................................................................. 31
PECL/LVDS/AMI Output Port Selection ............................................................................................................................... 32
Output Frequency Selection and Configuration .................................................................................................................. 32
Table of Contents
FINAL
Page 2
ACS8520 SETS
DATASHEET
www.semtech.com
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