Overview

The 8761 is a low voltage, low skew PCI / PCI-X Clock Generator. The 8761 has a selectable REF_CLK or crystal input. The REF_CLK input accepts LVCMOS or LVTTL input levels. The 8761 has a fully integrated PLL along with frequency configurable clock and feedback outputs for multiplying and regenerating clocks with "zero delay". Using a 20MHz or 25MHz crystal or a 33.333MHz or 66.666MHz reference frequency, the 8761 will generate output frequencies of 33.333MHz, 66.666MHz, 100MHz and 133.333MHz simultaneously. The low impedance LVCMOS/LVTTL outputs of the 8761 are designed to drive 50Ω series or parallel terminated transmission lines.

8761 - Block Diagram
8761 - Pinout
8761 - Block Diagram
8761 - Pinout
  • Fully integrated PLL
  • Seventeen LVCMOS/LVTTL outputs, 15? typical output impedance
  • Selectable crystal oscillator interface or LVCMOS/LVTTL REF_CLK
  • Maximum output frequency: 166.67MHz
  • Maximum crystal input frequency: 38MHz
  • Maximum REF_CLK input frequency: 83.33MHz
  • Individual banks with selectable output dividers for generating 33.333MHz, 66.66MHz, 100MHz and 133.333MHz simultaneously
  • Separate feedback control for generating PCI / PCI-X frequencies from a 20MHz or 25MHz crystal or 33.333MHz or 66.666MHz reference frequency
  • Cycle-to-cycle jitter: 70ps (maximum)
  • Period jitter, RMS: 17ps (maximum)
  • Output skew: 230ps (maximum)
  • Bank skew: 40ps (maximum)
  • Static phase offset: 0 ± 150ps (maximum)
  • Full 3.3V or 3.3V core, 2.5V multiple output supply modes
  • 0°C to 85°C ambient operating temperature
  • Available in lead-free RoHS-compliant package

Documentation

Design & Development

ECAD Models

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Product Options

    Processing table
    Pkg. Type
    Lead Count (#)
    Temp. Grade
    Pb (Lead) Free
    Carrier Type
    Buy / Sample
    Part Number
    8761CYLF
    circleObsolete
    memory
    view_in_ar
    		TQFP 64 C Yes Tray
    8761CYLFT
    circleObsolete
    memory
    view_in_ar
    		TQFP 64 C Yes Reel
    8761CYLN
    circleObsolete
    memory
    view_in_ar
    		TQFP 64 C Yes Tray
    8761CYLNT
    circleObsolete
    memory
    view_in_ar
    		TQFP 64 C Yes Reel
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