The 9EX21531 provides 15 output clocks for PCIe Gen1/ 2/3 applications. The 9EX21531 has 4 selectable SMBus addresses, and dedicated CKPWRGD/PD# and VDDA pins for easy board design. A differential clock from a CK410B+ or CK420BQ main clock generator, such as the 932S421, drives the 9EX21531. In fanout mode, the 9EX21531 provides outputs up to 166MHz.


  • 15 - 0.7V current mode differential HSCL output pairs
  • Pin compatible to 9EX21501/ Easy PCIe Gen3 upgrade
  • 4 Selectable SMBus Addresses/Mulitple devices can share the same SMBus Segment
  • 8 dedicated and 2 group OE# pins/Hardware control of the outputs
  • PLL or bypass mode/PLL can dejitter incoming clock
  • Selectable PLL bandwidth/minimizes jitter peaking in downstream PLL's
  • Spread Spectrum Compatible/tracks spreading input clock for low EMI
  • SMBus Interface/unused outputs can be disabled
  • Undriven differential outputs in Power Down mode/ Easy power management
  • Cycle-to-cycle jitter <50ps
  • Output-to-output skew < 150 ps
  • PCIe Gen3 phase jitter < 1.0ps RMS

Product Options

Orderable Part ID Part Status Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
Obsolete 64 C Yes Tray
Obsolete 64 C Yes Reel

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
9EX21531 Datasheet Datasheet PDF 257 KB
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 322 KB
AN-844 Termination - AC Coupling Clock Receivers Application Note PDF 170 KB
AN-843 PCI Express Reference Clock Requirements Application Note PDF 1.90 MB
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-836 Differential Input to Accept Single-ended Levels Application Note PDF 120 KB
AN-835 Differential Input with VCMR being VIH Referenced Application Note PDF 160 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-805 Recommended Ferrite Beads Application Note PDF 121 KB
PDN# : CQ-17-04(R1) Product Discontinuance Notice Product Discontinuation Notice PDF 606 KB
PDN# : CQ-17-04 Product Discontinuance Notice Product Discontinuation Notice PDF 599 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# : TB1504-01R1 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 95 KB
PCN# : TB1504-01 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 50 KB
Clock Distribution Overview 日本語 Overview PDF 217 KB
PCI Express Timing Solutions Overview Overview PDF 275 KB
Timing Solutions Products Overview Overview PDF 4.11 MB
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB