The 87974I is a low skew, low jitter 1-to-15 LVCMOS/ LVTTL Clock Generator/Zero Delay Buffer. The device has a fully integrated PLL and three banks whose divider ratios can be independently controlled, providing output frequency relationships of 1:1, 2:1, 3:1, 3:2, 3:2:1. In addition, the external feedback connection provides for a wide selection of output-to-input frequency ratios. The CLK0 and CLK1 pins allow for redundant clocking on the input and dynamically switching the PLL between two clock sources. Guaranteed low jitter and output skew characteristics make the 87974I ideal for those applications demanding well defined performance and repeatability.


  • Fully integrated PLL
  • Fifteen single ended 3.3V LVCMOS/LVTTL outputs
  • Two LVCMOS/LVTTL clock inputs for redundant clock applications
  • CLK0 and CLK1 accepts the following input levels: LVCMOS/LVTTL
  • Output frequency range: 8.33MHz to 125MHz
  • VCO range: 200MHz to 500MHz
  • External feedback for "zero delay" clock regeneration
  • Cycle-to-cycle jitter: ±100ps (typical)
  • Output skew: 350ps (maximum)
  • 3.3V operating supply
  • -40°C to 85°C ambient operating temperature
  • Available in lead-free RoHS-compliant package

Product Options

Orderable Part ID Part Status Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
Obsolete TQFP 52 I Yes Tray
Obsolete TQFP 52 I Yes Reel

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
87974I Datasheet Datasheet PDF 332 KB
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 322 KB
AN-845 Termination - LVCMOS Application Note PDF 146 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-805 Recommended Ferrite Beads Application Note PDF 121 KB
PDN# : TP-20-05(R1) Revised PDN - Change Replacement for 85411AMLF(T) from 5PB1102CMGI(8) to 8SLVP1102ANLGI(8) Product Discontinuation Notice PDF 743 KB
PDN# : TP-20-05 End-of-Life (EOL) Process on Select Part Numbers Product Discontinuation Notice PDF 715 KB
PCN# : A1401-02 Alternate Copper Wire Assembly Site Product Change Notice PDF 36 KB
PDN# : N-12-22R2 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 363 KB
PDN# : N-12-22R1 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 209 KB
87974I IBIS Model Model - IBIS ZIP 18 KB
Timing Solutions Products Overview Overview PDF 4.11 MB
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB