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ACS8520 Datasheet(PDF) 2 Page - Semtech Corporation |
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ACS8520 Datasheet(HTML) 2 Page - Semtech Corporation |
2 / 150 page ![]() Table of Contents Revision 3.02/October 2005 © Semtech Corp. Page 2 www.semtech.com ACS8520 SETS Section Page ADVANCED COMMUNICATIONS FINAL DATASHEET Description ................................................................................................................................................................................................. 1 Block Diagram............................................................................................................................................................................................ 1 Features ..................................................................................................................................................................................................... 1 Table of Contents ...................................................................................................................................................................................... 2 Pin Diagram ............................................................................................................................................................................................... 4 Pin Description........................................................................................................................................................................................... 5 Introduction................................................................................................................................................................................................ 8 General Description................................................................................................................................................................................... 8 Overview .............................................................................................................................................................................................8 Input Reference Clock Ports .......................................................................................................................................................... 10 Locking Frequency Modes.................................................................................................................................................... 10 PECL/LVDS/AMI Input Port Selection.................................................................................................................................. 11 Clock Quality Monitoring................................................................................................................................................................. 12 Activity Monitoring................................................................................................................................................................. 12 Frequency Monitoring ........................................................................................................................................................... 14 Selection of Input Reference Clock Source................................................................................................................................... 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 Modes of Operation ........................................................................................................................................................................ 16 Free-run Mode ....................................................................................................................................................................... 16 Pre-locked Mode ................................................................................................................................................................... 16 Locked Mode ......................................................................................................................................................................... 16 Lost-phase Mode................................................................................................................................................................... 17 Holdover Mode ...................................................................................................................................................................... 17 Pre-locked2 Mode ................................................................................................................................................................. 19 DPLL Architecture and Configuration ............................................................................................................................................ 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 Configuration for Redundancy Protection ..................................................................................................................................... 29 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 Output Clock Ports .......................................................................................................................................................................... 32 PECL/LVDS/AMI Output Port Selection ............................................................................................................................... 32 Output Frequency Selection and Configuration .................................................................................................................. 32 Table of 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