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87972I - Block Diagram
87972I - Pinout


Low Skew, 1-to-12 LVCMOS/LVTTL Clock Multiplier/Zero Delay Buffer

The 87972I is a low skew, LVCMOS/LVTTL Clock Generator. The 87972I has three selectable inputs and provides fourteen LVCMOS/LVTTL outputs. The 87972I is a highly flexible device. Using the crystal oscillator input, it can be used to generate clocks for a system. All of these clocks can be the same frequency or the device can be configured to generate up to three different frequencies among the three output banks. Using one of the single ended inputs, the 87972I can be used as a zero delay buffer/multiplier/divider in clock distribution applications. The three output banks and feedback output each have their own output dividers which allows the device to generate a multitude of different bank frequency ratios and output-toinput frequency ratios. In addition, 2 outputs in Bank C (QC2, QC3) can be selected to be inverting or non-inverting. The output frequency range is 8.33MHz to125MHz. Input frequency range is 5MHz to 120MHz. The 87972I also has a QSYNC output which can be used for system synchronization purposes. It monitors Bank A and Bank C outputs and goes low one period of the faster clock prior to coincident rising edges of Bank A and Bank C clocks. QSYNC then goes high again when the coincident rising edges of Bank A and Bank C occur. This feature is used primarily in applications where Bank A and Bank C are running at different frequencies, and is particularly useful when they are running at non-integer multiples of one another.


  • Fully integrated PLL
  • Fourteen LVCMOS/LVTTL outputs
  • (12) clocks, (1) feedback, (1) sync
  • Selectable crystal oscillator interface or LVCMOS/LVTTL reference clock inputs
  • CLK0, CLK1 can accept the following input levels: LVCMOS or LVTTL
  • Output frequency range: 8.33MHz to 125MHz
  • VCO range: 200MHz to 480MHz
  • Output skew: 550ps (maximum)
  • Cycle-to-cycle jitter: ±100ps (typical)
  • Full 3.3V supply voltage
  • -40°C to 85°C ambient operating temperature
  • Available in lead-free RoHS-compliant package
  • Compatible with PowerPC™ and Pentium™ Microprocessors

Product Specification

Outputs (#)Output TypeOutput Freq Range (MHz)Input Freq (MHz)Inputs (#)Input TypeOutput Banks (#)Core Voltage (V)Output Voltage (V)
13LVCMOS8.330000 - 125.00000010.000000 - 120.0000003LVCMOS, Crystal43.33.3

Product Options

Orderable Part IDPart StatusPkg. CodePkg. TypeLead Count (#)Temp. GradePb (Lead) FreeCarrier TypeSample & Buy
87972DYILFActivePPG52TQFP52IYesTrayCheck Availability
87972DYILFTActivePPG52TQFP52IYesReelCheck Availability


Technical Documentation

Title Other Languages Type Format File Size Datesort icon
Datasheets & Errata
87972I Datasheet Datasheet PDF 182 KB Jan 26, 2016
Apps Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 229 KB Jul 5, 2016
AN-844 Termination - AC Coupling Clock Receivers Application Note PDF 82 KB May 13, 2014
AN-845 Termination - LVCMOS Application Note PDF 62 KB May 13, 2014
show all (11)
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 403 KB May 12, 2014
AN-840 Jitter Specifications for Timing Signals Application Note PDF 349 KB May 8, 2014
AN-836 Differential Input to Accept Single-ended Levels Application Note PDF 37 KB May 6, 2014
AN-834 Hot-Swap Recommendations Application Note PDF 67 KB May 6, 2014
AN-835 Differential Input with VCMR being VIH Referenced Application Note PDF 77 KB May 6, 2014
AN-815 Understanding Jitter Units Application Note PDF 476 KB Apr 24, 2014
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.06 MB Apr 24, 2014
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB Jan 15, 2014
PCN# : A1401-02 Alternate Copper Wire Assembly Site Product Change Notice PDF 36 KB Feb 16, 2014
PDN# : N-12-22R2 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 363 KB Jun 14, 2013
PDN# : N-12-22R1 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 209 KB Feb 28, 2013
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB Apr 28, 2016
IDT Clock Distribution Overview 日本語 Overview PDF 3.79 MB Apr 25, 2016

Software & Tools

Title Type Format File Size Datesort icon
87972I IBIS Model Model - IBIS ZIP 6 KB Apr 17, 2006