NOTICE - The following device(s) are recommended alternatives:
9ZXL1251E - 12-Output DB1200ZL PCIe Clock Clock Buffer
Pin-to-pin with improved performance

The IDT9ZX21201 is a 12-output DB1200Z suitable for PCI Express® Gen3 or QPI applications. The part is backwards compatible to PCIe Gen1 and Gen2. A fixed external feedback maintains low drift for critical QPI applications. In bypass mode, the IDT9ZX21201 can provide outputs up to 150MHz.


  • Cycle-to-cycle jitter <50ps
  • Output-to-output skew < 65 ps
  • Input-to-output delay variation <50ps
  • PCIe Gen3 phase jitter < 1.0ps RMS
  • QPI 9.6GT/s 12UI phase jitter < 0.2ps RMS
  • Space-saving 64-pin packages
  • Fixed feedback path/ 0ps input-to-output delay
  • 9 Selectable SMBus Addresses/Mulitple devices can share the same SMBus Segment
  • 12 OE# pins/Hardware control of each output
  • PLL or bypass mode/PLL can dejitter incoming clock
  • 100MHz or 133MHz PLL mode operation/supports PCIe and QPI applications
  • Selectable PLL bandwidth/minimizes jitter peaking in downstream PLL's
  • Spread Spectrum Compatible/tracks spreading input clock for low EMI
  • Software control of PLL Bandwidth and Bypass Settings/ PLL can dejitter incoming clock (B Rev only)

Product Options

Orderable Part ID Part Status Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Package Buy Sample
9ZX21201AKLF Active VFQFPN 64 C Yes Tray Package Info
9ZX21201AKLFT Active VFQFPN 64 C 1 Reel Package Info
9ZX21201BKLF Active VFQFPN 64 C Yes Tray Package Info
9ZX21201BKLFT Active VFQFPN 64 C Yes Reel Package Info

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
9ZX21201 Datasheet Datasheet PDF 412 KB
Application Notes & White Papers
AN-975 Cascading PLLs Application Note PDF 255 KB
AN-828 Termination - LVPECL Application Note PDF 322 KB
AN-844 Termination - AC Coupling Clock Receivers Application Note PDF 170 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-834 Hot-Swap Recommendations Application Note PDF 153 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-808 PCI Express/HCSL Termination Application Note PDF 137 KB
AN-805 Recommended Ferrite Beads Application Note PDF 121 KB
PCN# : A1904-01 Add Greatek, Taiwan as an Alternate Assembly Facility Product Change Notice PDF 983 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
PCN# : A1311-03R1 Alternate Assembly Locations Product Change Notice PDF 43 KB
PCN# : A1311-03 Alternate Assembly Locations Product Change Notice PDF 140 KB
PCN# : A1305-01 Gold Wire to Copper Wire Product Change Notice PDF 148 KB
9ZX21201B IBIS Model Model - IBIS ZIP 12 KB
9ZX21201A IBIS Model Model - IBIS ZIP 12 KB
Timing Solutions Products Overview Overview PDF 4.11 MB
9ZX21201 Reference Schematic Schematic PDF 42 KB
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB
IDT Clock Distribution Overview 日本語 Overview PDF 3.79 MB
9ZX21201 Block Diagram Block Diagram PNG 30 KB