Clocks & Timing

Overview

The 844256DI is a Crystal-to-LVDS Clock Synthesizer/Fanout Buffer designed for SONET and Gigabit Ethernet applications. The output frequency can be set using the frequency select pins and a 25MHz crystal for Ethernet frequencies, or a 19.44MHz crystal for SONET. The low phase noise characteristics of the 844256DI make it an ideal clock for these demanding applications.

844256DI - Block Diagram
844256DI - Pinout
844256I - Block Diagram
844256DI - Block Diagram
844256DI - Pinout
844256I - Block Diagram
  • Six differential LVDS output pairs
  • Crystal oscillator interface
  • Output frequency range: 62.5MHz - 625MHz
  • Crystal input frequency range:15.625MHz - 25.5MHz
  • RMS phase jitter @ 125MHz, using a 25MHz crystal (1.875MHz – 20MHz): 0.43ps (typical)
  • Full 3.3V or mixed 3.3V core, 2.5V output supply mode
  • -40°C to 85°C ambient operating temperature
  • Available in lead-free (RoHS 6) package

Documentation

Title Type Date
ICS844256DI Datasheet
PDF989 KB
Datasheet
AN-805 Recommended Ferrite Beads
PDF91 KB
Application Note
AN-827 Application Relevance of Clock Jitter
PDF1.99 MB
Application Note
AN-828 Termination - LVPECL
PDF322 KB
Application Note
AN-831 The Crystal Load curve
PDF395 KB
Application Note
AN-846 Termination - LVDS
PDF133 KB
Application Note
AN-842 Thermal Considerations in Package Design and Selection
PDF495 KB
Application Note
AN-840 Jitter Specifications for Timing Signals
PDF442 KB
Application Note
AN-838 Peak-to-Peak Jitter Calculations
PDF115 KB
Application Note
AN-839 RMS Phase Jitter
PDF233 KB
Application Note
AN-832 Timing Budget and Accuracy
PDF131 KB
Application Note
AN-834 Hot-Swap Recommendations
PDF153 KB
Application Note
AN-837 Overdriving the Crystal Interface
PDF133 KB
Application Note
AN-830 Quartz Crystal Drive Level
PDF143 KB
Application Note
AN-815 Understanding Jitter Units
PDF565 KB
Application Note
AN-802 Crystal-Measuring Oscillator Negative Resistance
PDF136 KB
Application Note
AN-801 Crystal-High Drive Level
PDF202 KB
Application Note
AN-806 Power Supply Noise Rejection
PDF438 KB
Application Note
AN-803 Crystal Timing Budget and Accuracy for Renesas Timing Clock Products
PDF108 KB
Application Note
PDN#: CQ-19-04 Product Discontinuance Notice
PDF1010 KB
End Of Life Notice
IDT Clock Generation Overview
PDF1.83 MB
Overview
PCN# : A1606-02 Add Greatek Taiwan as Alternate Assembly
PDF567 KB
Product Change Notice
PCN# : A1309-01 Changed of Traceability Mark Format
PDF439 KB
Product Change Notice
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products
PDF361 KB
Product Change Notice
PCN# : A1208-01R1 Gold to Copper Wire
PDF254 KB
Product Change Notice

Design & Development

Software Downloads

Title Type Date
PDN#: CQ-19-04 Product Discontinuance Notice
PDF1010 KB
End Of Life Notice

ECAD Models

Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on products in the Product Options table. If a symbol or model isn't available, it can be requested directly from the website.

Explore ECAD Models

Models

Title Type Date
844256i IBIS Model
ZIP50 KB
Model - IBIS

Product Options

    Processing table
    Part Number
    Pkg. Type
    Lead Count (#)
    Temp. Grade
    Pb (Lead) Free
    Carrier Type
    Buy / Sample
    844256DGILF
    block_flippedObsolete
    memory
    view_in_ar
    		TSSOP 24 I Yes Tube
    844256DGILFT
    block_flippedObsolete
    memory
    view_in_ar
    		TSSOP 24 I Yes Reel
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