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

The 843751 is a low jitter, high performance clock generator. The 843751 is designed for use in the SAS-2 interconnect and the three transport protocols that use the SAS-2 interconnect: Serial SCSI Protocol (SSP), Serial ATA Tunneled Protocol (STP), and Serial Management Protocol (SMP). The 843751 has excellent (<1ps) RMS phase jitter, over the SAS defined integration range. The 843751 uses an external, 25MHz, parallel resonant crystal to generate 75MHz. This silicon based approach provides excellent frequency stability and reliability. The 843751 features up, down, and center spread spectrum (SSC) clocking techniques. The up, down and center SSC will be required in the SAS-2 applications that have three clock trees in the HBA and expander ASICs.


  • Designed for use in SAS, SAS-2 systems
  • Up, down and center Spread Spectrum Clocking (SSC)
  • One differential 3.3V or 2.5V LVPECL output pair
  • Output frequency: 75MHz
  • RMS phase jitter @ 75MHz, (900kHz – 7.5MHz): 0.734ps (typical) @ 3.3V
  • 3.3V or 2.5V operating supply modes
  • 0°C to 70°C ambient operating temperature
  • Available in lead-free (RoHS 6) package

Product Options

Orderable Part ID Part Status Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
Obsolete SOIC 8 C Yes Tube
Obsolete SOIC 8 C Yes Reel

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
843751 Datasheet Datasheet PDF 304 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-842 Thermal Considerations in Package Design and Selection Application Note PDF 495 KB
AN-803 Crystal Timing Budget and Accuracy for IDT Timing Clock Products Application Note PDF 128 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-834 Hot-Swap Recommendations Application Note PDF 153 KB
AN-837 Overdriving the Crystal Interface Application Note PDF 133 KB
AN-832 Timing Budget and Accuracy Application Note PDF 131 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
PCN# : TB1504-01R1 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 95 KB
PDN# : CQ-15-04 Quarterly Market Declined PDN Product Discontinuation Notice PDF 545 KB
PCN# : TB1504-01 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 50 KB
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB
843751 IBIS Model Model - IBIS ZIP 64 KB
Clock Distribution Overview 日本語 Overview PDF 217 KB
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