Overview

The 87949I is a low skew, ÷1, ÷2 Clock Generator. The 87949I has selectable single ended clock or LVPECL clock inputs. The single ended clock input accepts LVCMOS or LVTTL input levels. The PCLK, nPCLK pair can accept LVPECL, CML, or SSTL input levels. The low impedance LVCMOS outputs are designed to drive 50? series or parallel terminated transmission lines. The effective fanout can be increased from 15 to 30 by utilizing the ability of the outputs to drive two series terminated lines. The divide select inputs, DIV_SELx, control the output frequency of each bank. The outputs can be utilized in the ÷1, ÷2 or a combination of ÷1 and ÷2 modes. The master reset input, MR/nOE, resets the internal frequency dividers and also controls the active and high impedance states of all outputs. The 87949I is characterized at 3.3V core/3.3V output. Guaranteed output and part-to-part skew characteristics make the 87949I ideal for those clock distribution applications demanding well defined performance and repeatability.

87949I - Block Diagram
87949I - Pinout
87949I - Block Diagram
87949I - Pinout
  • Fifteen single ended LVCMOS outputs, 7? typical output impedance
  • Selectable LVCMOS or LVPECL clock inputs
  • CLK0 and CLK1 can accept the following input levels: LVCMOS and LVTTL
  • PCLK, nPCLK supports the following input types: LVPECL, CML, SSTL
  • Maximum output frequency: 160MHz
  • Output skew: 350ps (maximum)
  • Part-to-part skew: 2.75ns (maximum)
  • 3.3V supply voltage
  • -40°C to 85°C ambient operating temperature
  • Available in lead-free RoHS compliant packages

Documentation

Design & Development

ECAD Models

Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on products in the Product Options table. If a symbol or model isn't available, it can be requested directly from the website.

Explore ECAD Models
Diagram of ECAD Models

Product Options

    Processing table
    Pkg. Type
    Lead Count (#)
    Temp. Grade
    Pb (Lead) Free
    Carrier Type
    Buy / Sample
    Part Number
    87949AYILF
    circleObsolete
    memory
    view_in_ar
    		TQFP 52 I Yes Tray
    87949AYILFT
    circleObsolete
    memory
    view_in_ar
    		TQFP 52 I Yes Reel
    Parametric Table tips

    Tips for Using This Parametric Table:

    • Hide Filters button in header: Collapse or expands filters
    • Column sort buttons in header: Sort Column alphabetically / numerically descending or ascending
    • Reset button in header: Reset all filters to the page default
    • Full Screen button in header: Expand the table to full screen view (user must close out of full screen before they can interact with rest of page)
    • Export button in header: Export the filtered results of the table to an Excel document
    • Filter parts search bar in header: Type to filter table results by part number
    • Hide column button in column headers: Select to hide columns in table
    • AND / OR toggle switches in header: Toggles the logic of this particular filter to be “AND” or “OR” logic for filtering results
    • Multiselect checkboxes at beginning of each row in table: Select these checkboxes to compare products against each other
    • Document icon next to product name in row: View the featured document for this product
    • Chip icon next to the right of the document icon in row: View the block diagram for this product
    • Cart icon to the right of the chip icon: Indicates that samples are available for this product