Low Voltage/Low Skew,1:8 PCI/PCI-X Zero Delay Clock Generator

The 87608I has a selectable REF_CLK or crystal input. The REF_CLK input accepts LVCMOS or LVTTL input levels. The 87608I has a fully integrated PLL along with frequency configurable clock and feedback outputs for multiplying and regenerating clocks with "zero delay". The 87608I is a 1:8 PCI/PCI-X Clock Generator. The 87608I has a selectable REF_CLK or crystal input. The REF_CLK input accepts LVCMOS or LVTTL input levels. The 87608I has a fully integrated PLL along with frequency configurable clock and feedback outputs for multiplying and regenerating clocks with "zero delay". The PLL's VCO has an operating range of 250MHz-500MHz, allowing this device to be used in a variety of general purpose clocking applications. For PCI/PCI-X applications in particular, the VCO frequency should be set to 400MHz. This can be accomplished by supplying 33.33MHz, 25MHz, 20MHz, or 16.66MHz on the reference clock or crystal input and by selecting ÷12, ÷16, ÷20, or ÷24, respectively as the feedback divide value. The dividers on each of the two output banks can then be independently configured to generate 33.33MHz (÷12), 66.66MHz (÷6), 100MHz (÷4), or 133.33MHz (÷3). The 87608I is characterized to operate with its core supply at 3.3V and each bank supply at 3.3V or 2.5V. The 87608I is packaged in a small 7x7mm body LQFP, making it ideal for use in space-constrained applications.

Features

  • Fully integrated PLL
  • Eight LVCMOS/LVTTL outputs, 15? typical output impedance
  • Selectable crystal oscillator interface or LVCMOS/LVTTL REF_IN clock input
  • Maximum output frequency: 166.67MHz
  • Maximum crystal input frequency: 38MHz
  • Maximum REF_IN input frequency: 41.67MHz
  • Individual banks with selectable output dividers for generating 33.333MHz, 66.66MHz, 100MHz and 133.333MHz
  • Separate feedback control for generating PCI / PCI-X frequencies from a 16.66MHz or 20MHz crystal, or 25MHz or 33.33MHz reference frequency
  • VCO range: 200MHz to 500MHz
  • Cycle-to-cycle jitter: 120ps (maximum), @ 3.3V
  • Period jitter, RMS: 20ps (maximum)
  • Output skew: 250ps (maximum)
  • Bank skew: 60ps (maximum)
  • Static phase offset: 160ps ± 160ps
  • Voltage Supply Modes:
    VDD (core/inputs), VDDA (analog supply for PLL),
    VDDOA (output bank A),
    VDDOB (output bank B, REF_OUT, FB_OUT)
    VDD/VDDA/VDDOA/VDDOB
    3.3/3.3/3.3/3.3
    3.3/3.3/2.5/3.3
    3.3/3.3/3.3/2.5
    3.3/3.3/2.5/2.5
  • -40°C to 85°C ambient operating temperature
  • Available in lead-free RoHS compliant package

Product Options

Orderable Part ID Part Status Pkg. Code Pkg. Type Lead Count (#) Temp. Grade Pb (Lead) Free Carrier Type Buy Sample
87608AYILF Active PRG32 TQFP 32 I Yes Tray Availability
87608AYILFT Active PRG32 TQFP 32 I Yes Reel Availability

Technical Documentation

Title Other Languages Type Format File Size Date
Datasheets & Errata
87608I Datasheet Datasheet PDF 153 KB Jan 24, 2016
Application Notes & White Papers
AN-828 Termination - LVPECL Application Note PDF 229 KB Jul 5, 2016
AN-835 Differential Input with VCMR being VIH Referenced Application Note PDF 77 KB May 10, 2014
AN-815 Understanding Jitter Units Application Note PDF 476 KB Apr 23, 2014
AN-845 Termination - LVCMOS Application Note PDF 62 KB May 12, 2014
AN-844 Termination - AC Coupling Clock Receivers Application Note PDF 82 KB May 12, 2014
AN-842 Thermal Considerations in Package Design and Selection Application Note PDF 403 KB May 11, 2014
AN-840 Jitter Specifications for Timing Signals Application Note PDF 349 KB May 7, 2014
AN-836 Differential Input to Accept Single-ended Levels Application Note PDF 37 KB May 5, 2014
AN-834 Hot-Swap Recommendations Application Note PDF 67 KB May 5, 2014
AN-827 Application Relevance of Clock Jitter Application Note PDF 1.06 MB Apr 23, 2014
AN-805 Recommended Ferrite Beads Application Note PDF 38 KB Jan 14, 2014
PCNs & PDNs
PCN# : A1602-01(R1) Add Greatek Taiwan as Alternate Assembly Product Change Notice PDF 611 KB Apr 13, 2016
PCN# : A1602-01 Add Greatek Taiwan as Alternate Assembly Product Change Notice PDF 611 KB Feb 14, 2016
PCN# : TB1504-01R1 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 95 KB Oct 21, 2015
PCN# : TB1504-01 Qty per Reel Standardization for Selective Packages Product Change Notice PDF 50 KB Jul 20, 2015
PCN# : A1401-02 Alternate Copper Wire Assembly Site Product Change Notice PDF 36 KB Feb 15, 2014
PDN# : N-12-22R2 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 363 KB Jun 13, 2013
PCN# : TB1303-01 Change of Carrier Tape for TQFP-32, TQFP-48 Product Change Notice PDF 472 KB Mar 30, 2013
PDN# : N-12-22R1 PRODUCT DISCONTINUANCE NOTICE Product Discontinuation Notice PDF 209 KB Feb 27, 2013
Other
The IDT Consumer Products Advantage Overview PDF 4.01 MB Jun 30, 2017
The IDT Automotive Advantage Overview PDF 3.55 MB May 26, 2017
The IDT Communications Products Advantage Overview PDF 2.54 MB Feb 13, 2017
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 24, 2016

Software & Tools

Title Other Languages Type Format File Size Date
87608I IBIS Model Model - IBIS ZIP 67 KB Nov 3, 2009

News & Additional Resources