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.

Features

  • 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

Product Options

Part Number Part Status Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
Obsolete TSSOP 24 I Yes Tube
Availability
Obsolete TSSOP 24 I Yes Reel
Availability

Documentation & Downloads

Title language Type Format File Size Date
Datasheets & Errata
ICS844256DI Datasheet Datasheet PDF 989 KB
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 322 KB
AN-831 The Crystal Load curve Application Note PDF 395 KB
AN-846 Termination - LVDS Application Note PDF 133 KB
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 495 KB
AN-840 Jitter Specifications for Timing Signals Application Note PDF 442 KB
AN-838 Peak-to-Peak Jitter Calculations Application Note PDF 115 KB
AN-839 RMS Phase Jitter Application Note PDF 233 KB
AN-837 Overdriving the Crystal Interface Application Note PDF 133 KB
AN-832 Timing Budget and Accuracy Application Note PDF 131 KB
AN-834 Hot-Swap Recommendations Application Note PDF 153 KB
AN-830 Quartz Crystal Drive Level Application Note PDF 143 KB
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.15 MB
AN-815 Understanding Jitter Units Application Note PDF 565 KB
AN-802 Crystal-Measuring Oscillator Negative Resistance Application Note PDF 136 KB
AN-801 Crystal-High Drive Level Application Note PDF 202 KB
AN-806 Power Supply Noise Rejection Application Note PDF 438 KB
AN-805 Recommended Ferrite Beads Application Note PDF 121 KB
AN-803 Crystal Timing Budget and Accuracy for Renesas Timing Clock Products Application Note PDF 108 KB
PCNs & PDNs
PDN#: CQ-19-04 Product Discontinuance Notice Product Discontinuation Notice PDF 1010 KB
PCN# : A1606-02 Add Greatek Taiwan as Alternate Assembly Product Change Notice PDF 567 KB
PCN# : A1309-01 Changed of Traceability Mark Format Product Change Notice PDF 439 KB
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB
PCN# : A1208-01R1 Gold to Copper Wire Product Change Notice PDF 254 KB
Downloads
844256i IBIS Model Model - IBIS ZIP 50 KB
Other
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB