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.

Features

  • 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 Options

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

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
87972I Datasheet Datasheet PDF 276 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-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
PCNs & PDNs
PDN# : CQ-18-03 Product Discontinuance Notice Product Discontinuation Notice PDF 218 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
Downloads
87972I IBIS Model Model - IBIS ZIP 6 KB
Other
Clock Distribution Overview 日本語 Overview PDF 217 KB
Timing Solutions Products Overview Overview PDF 4.11 MB
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB