The 841N254I is a 4-output clock synthesizer designed for S-RIO 1.3 and 2.0 reference clock applications. The device generates four copies of a selectable 250MHz, 156.25MHz, 125MHz or 100MHz clock signal with excellent phase jitter performance. The four outputs are organized in two banks of two LVDS and two HCSL outputs. The device uses IDT's fourth generation FemtoClock® NG technology for an optimum of high clock frequency and low phase noise performance, combined with a low power consumption and high power supply noise rejection. The synthesized clock frequency and the phase-noise performance are optimized for driving RIO 1.3 and 2.0 SerDes reference clocks. The device supports 3.3V and 2.5V voltage supplies and is packaged in a small 32-lead VFQFN package. The extended temperature range supports wireless infrastructure, telecommunication and networking end equipment requirements.

Features

  • Fourth generation FemtoClock® (NG) technology
  • Selectable 250MHz, 156.25MHz, 125MHz or 100MHz output clock synthesized from a 25MHz fundamental mode crystal
  • Four differential clock outputs (two LVDS and two HCSL outputs)
  • Crystal interface designed for 25MHz, parallel resonant crystal
  • RMS phase jitter at 156.25MHz, using a 25MHz crystal (1MHz - 20MHz): 0.27ps (typical)
  • RMS phase jitter at 156.25MHz, using a 25MHz crystal (12kHz - 20MHz): 0.32ps (typical)
  • Power supply noise rejection PSNR: -50dB (typical)
  • LVCMOS interface levels for the frequency select input
  • Full 3.3V or 2.5V supply voltage
  • Available in Lead-free (RoHS 6) package
  • -40°C to 85°C ambient operating temperature

Product Options

Orderable Part ID Part Status Pkg. Code Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
841N254BKILF Active NLG32P1 VFQFPN 32 I Yes Tray
Availability
841N254BKILFT Active NLG32P1 VFQFPN 32 I Yes Reel
Availability

Technical Documentation

Title Other Languages Type Format File Size Date
Datasheets & Errata
841N254B Datasheet Datasheet PDF 507 KB
User Guides & Manuals
Timing Solutions for Cavium Processor Designs Guide PDF 810 KB
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 229 KB
AN-831 The Crystal Load curve Application Note PDF 308 KB
AN-846 Termination - LVDS Application Note PDF 50 KB
AN-844 Termination - AC Coupling Clock Receivers Application Note PDF 82 KB
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 403 KB
AN-835 Differential Input with VCMR being VIH Referenced Application Note PDF 77 KB
AN-803 Crystal Timing Budget and Accuracy for IDT Timing Clock Products Application Note PDF 44 KB
AN-840 Jitter Specifications for Timing Signals Application Note PDF 349 KB
AN-839 RMS Phase Jitter Application Note PDF 149 KB
AN-838 Peak-to-Peak Jitter Calculations Application Note PDF 32 KB
AN-834 Hot-Swap Recommendations Application Note PDF 67 KB
AN-837 Overdriving the Crystal Interface Application Note PDF 50 KB
AN-836 Differential Input to Accept Single-ended Levels Application Note PDF 37 KB
AN-832 Timing Budget and Accuracy Application Note PDF 48 KB
AN-830 Quartz Crystal Drive Level Application Note PDF 59 KB
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.06 MB
AN-815 Understanding Jitter Units Application Note PDF 476 KB
AN-802 Crystal-Measuring Oscillator Negative Resistance Application Note PDF 52 KB
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB
AN-801 Crystal-High Drive Level Application Note PDF 109 KB
AN-806 Power Supply Noise Rejection Application Note PDF 353 KB
PCNs & PDNs
PCN# : A1904-01 Add Greatek, Taiwan as an Alternate Assembly Facility Product Change Notice PDF 983 KB
PDN# : CQ-18-03 Product Discontinuance Notice Product Discontinuation Notice PDF 218 KB
PCN# : A1611-02 Add JCET China as Alternate Assembly and Change of Material Set at Alternate Assembly Location Product Change Notice PDF 583 KB
PCN# : A1511-01(R1) Add SPEL India as Alternate Assembly Location Product Change Notice PDF 596 KB
PCN# : A1511-01 Add SPEL India as Alternate Assembly Location Product Change Notice PDF 544 KB
PCN# : N1309-01 Die Revision Change Product Change Notice PDF 56 KB
PCN# : W1308-01 Change of Passivation Thickness Product Change Notice PDF 941 KB
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB
Other
Timing Solutions Products Overview Overview PDF 4.11 MB
IDT Products for Radio Applications 日本語 Product Brief PDF 2.34 MB
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB
IDT Clock Distribution Overview 日本語 Overview PDF 3.79 MB

Software & Tools

Title Other Languages Type Format File Size Date
841N254I IBIS Model Model - IBIS ZIP 131.38 MB