FemtoClock® Crystal-to-LVDS Clock Generator

NOTICE - The following device(s) are recommended alternatives:

The 844251I-14 is an Ethernet Clock Generator. The 844251I-14 uses an 18pF parallel resonant crystal over the range of 23.2MHz – 30MHz. For Ethernet applications, a 25MHz crystal is used. The device has excellent <1ps phase jitter performance, over the 1.875MHz – 20MHz integration range. The 844251I-14 is packaged in a small 8-pin TSSOP, making it ideal for use in systems with limited board space.

Features

  • One differential LVDS output pair
  • Crystal oscillator interface designed for an 18pF, parallel resonant crystal (23.2MHz – 30MHz)
  • Output frequency ranges: 145MHz – 187.5MHz and 580MHz – 750MHz
  • VCO range: 580MHz – 750MHz
  • RMS phase jitter at 156.25MHz, using a 25MHz crystal (1.875MHz – 20MHz): 0.53ps (typical)
  • Full 2.5V output supply mode
  • -40°C to 85°C ambient operating temperature
  • Available in lead-free (RoHS 6) package

Product Options

Orderable Part ID Part Status Pkg. Code Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
844251BGI-14LF Obsolete PGG8 TSSOP 8 I Yes Tube Availability
844251BGI-14LFT Obsolete PGG8 TSSOP 8 I Yes Reel Availability

Technical Documentation

Title Other Languages Type Format File Size Date
Datasheets & Errata
844251I-14 Datasheet Datasheet PDF 236 KB Jun 2, 2016
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 229 KB Jul 5, 2016
AN-831 The Crystal Load curve Application Note PDF 308 KB Sep 22, 2014
AN-846 Termination - LVDS Application Note PDF 50 KB May 12, 2014
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 403 KB May 11, 2014
AN-803 Crystal Timing Budget and Accuracy for IDT Timing Clock Products Application Note PDF 44 KB May 7, 2014
AN-840 Jitter Specifications for Timing Signals Application Note PDF 349 KB May 7, 2014
AN-839 RMS Phase Jitter Application Note PDF 149 KB May 6, 2014
AN-838 Peak-to-Peak Jitter Calculations Application Note PDF 32 KB May 6, 2014
AN-834 Hot-Swap Recommendations Application Note PDF 67 KB May 5, 2014
AN-837 Overdriving the Crystal Interface Application Note PDF 50 KB May 5, 2014
AN-832 Timing Budget and Accuracy Application Note PDF 48 KB May 5, 2014
AN-830 Quartz Crystal Drive Level Application Note PDF 59 KB May 4, 2014
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.06 MB Apr 23, 2014
AN-815 Understanding Jitter Units Application Note PDF 476 KB Apr 23, 2014
AN-802 Crystal-Measuring Oscillator Negative Resistance Application Note PDF 52 KB Mar 11, 2014
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB Jan 14, 2014
AN-801 Crystal-High Drive Level Application Note PDF 109 KB Jan 14, 2014
AN-806 Power Supply Noise Rejection Application Note PDF 353 KB Jan 14, 2014
PCNs & PDNs
PDN# : CQ-16-01 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 552 KB May 3, 2016
PCN# : A1602-01(R1) Add Greatek Taiwan as Alternate Assembly Product Change Notice PDF 611 KB Apr 13, 2016
PCN# : A1602-01 Add Greatek Taiwan as Alternate Assembly Product Change Notice PDF 611 KB Feb 14, 2016
PCN# : A1511-01(R1) Add SPEL India as Alternate Assembly Location Product Change Notice PDF 596 KB Jan 27, 2016
PCN# : A1511-01 Add SPEL India as Alternate Assembly Location Product Change Notice PDF 544 KB Nov 12, 2015
PCN# : A1309-01 Changed of Traceability Mark Format Product Change Notice PDF 439 KB Oct 10, 2013
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB Mar 23, 2013
Other
The IDT Communications Products Advantage Overview PDF 4.00 MB Mar 21, 2018
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB Apr 28, 2016
IDT Clock Distribution Overview 日本語 Overview PDF 3.79 MB Apr 24, 2016