Overview

The 844N255I is a 6-output clock synthesizer designed for wireless infrastructure clock applications. The device uses IDT's fourth generation FemtoClock® NG technology for an optimum of high clock frequency and low phase noise performance, combined with a low power consumption and high power supply noise rejection. The reference frequency is selectable and the following frequency is supported: 25MHz. The synthesizer generates selectable 156.25MHz, 125MHz, 100MHz, 50MHz and 25MHz clock signals. The device is optimized for very low phase noise and cycle to cycle jitter. The synthesized clock frequency and the phase-noise performance are optimized for driving SRIO 1.3 and 2.0 SerDes reference, DSP and host-processor clocks. The device supports a 2.5V voltage supply and is packaged in a small, lead-free (RoHS 6) 48-lead VFQFN package. The extended temperature range supports wireless infrastructure, telecommunication and networking end equipment requirements.

844N255I - Block Diagram
844N255I - Pinout
844N255I - Block Diagram
844N255I - Pinout
  • 4TH generation FemtoClock® NG technology
  • Selectable 156.25MHz, 125MHz, 100MHz, 50MHz and 25MHz output clock signals synthesized from a 25MHz reference frequency
  • Six differential LVDS clock outputs
  • Crystal interface designed for a 25MHz crystal
  • RMS phase jitter @ 156.25MHz, using a 25MHz crystal (1MHz - 20MHz): 0.27ps (typical)
  • Internal regulator for optimum noise rejection
  • LVCMOS interface levels for the frequency select and output enable inputs
  • Full 2.5V supply voltage
  • Lead-free (RoHS 6) 48-lead VFQFN package
  • -40°C to 85°C ambient operating temperature

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.

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Product Options

    Processing table
    Pkg. Type
    Lead Count (#)
    Temp. Grade
    Pb (Lead) Free
    Carrier Type
    Buy / Sample
    Part Number
    844N255AKILF
    circleObsolete
    memory
    view_in_ar
    		VFQFPN 48 I Yes Tray
    844N255AKILFT
    circleObsolete
    memory
    view_in_ar
    		VFQFPN 48 I Yes Reel
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