National Semiconductor | High-performance Analog

 

 LM98725   
Three Channel, 16-Bit, 81 MSPS Analog Front End with LVDS/CMOS Output and Integrated CCD/CIS Sensor Timing Generator 		Click link to Download

Features

  • LVDS/CMOS Outputs
  • LVDS/CMOS/Crystal Clock Source with PLL Multiplication
  • Integrated Flexible Spread Spectrum Clock Generation
  • CDS or S/H Processing for CCD or CIS sensors
  • Independent Gain/Offset Correction for Each Channel
  • Automatic per-Channel Gain and Offset Calibration
  • Programmable Input Clamp Voltage
  • Flexible CCD/CIS Sensor Timing Generator

    • Description

    The LM98725 is a fully integrated, high performance 16-Bit, 81 MSPS signal processing solution for digital color copiers, scanners, and other image processing applications. High-speed signal throughput is achieved with an innovative architecture utilizing Correlated Double Sampling (CDS), typically employed with CCD arrays, or Sample and Hold (S/H) inputs (for higher speed CCD or CMOS image sensors). The signal paths utilize 8 bit Programmable Gain Amplifiers (PGA), a +/-9-Bit offset correction DAC and independently controlled Digital Black Level correction loops for each input. The PGA and offset DAC are programmed independently allowing unique values of gain and offset for each of the three analog inputs. The signals are then routed to a 81MHz high performance analog-to-digital converter (ADC). The fully differential processing channel shows exceptional noise immunity, having a very low noise floor of -74dB. The 16-bit ADC has excellent dynamic performance making the LM98725 transparent in the image reproduction chain.

    A very flexible integrated Spread Spectrum Clock Generation (SSCG) modulator is included to assist with EM compliance and reduce system costs.

    Key Specification

    Maximum Input Level

    1.2 or 2.4 Volt Modes

    (both with + or - polarity option)

    ADC Resolution

    16-Bit

    ADC Sampling Rate

    81 MSPS

    INL

    +17/- 28 LSB (typ)

    Channel Sampling Rate

    30/30/27 MSPS

    PGA Gain Steps

    256 Steps

    PGA Gain Range

    0.62 to 8.3x

    Analog DAC Resolution

    +/-9 Bits

    Analog DAC Range

    +/-307mV or +/-614mV

    Digital DAC Resolution

    +/-6 Bits

    Digital DAC Range

    -2048 LSB to + 2016 LSB

    SNR

    -74dB (@0dB PGA Gain)

    Power Dissipation

    755mW (LVDS)

    Operating Temp

    0 to 70°C

    Supply Voltage

    3.3V Nominal (3.0V to 3.6V range)


    Applications

  • Multi-Function Peripherals
  • High-speed Currency/Check Scanners
  • Flatbed or Handheld Color Scanners
  • High-speed Document Scanners

    • Also Recommended
    LM98519▲For A 6-channel AFE, With CMOS Outputs
    LM98620▲For A 6-channel AFE, With LVDS Outputs
    LM98714▲For A Lower-Speed Part With Fewer Features


    Typical Application

    Parameters / ValuesLM98725 LM98519 LM98620 LM98714
    Input Channels3 6 6 3
    ADC Sampling Rate81 MSPS 65 MSPS 70 MSPS 45 MSPS
    Channel Sampling Rate (MSPS)3 to 30 5 to 32.5 5 to 35 15 to 30
    ADC Resolution16 bits 10 bits 10 bits 16 bits
    Input Signal PolarityBoth Pos, Neg Negative Both Pos, Neg Both
    Input Sampler TypeBoth SH, CDS Both SH, CDS Both SH, CDS Both SH, CDS
    Integrated Timing GeneratorYes No No Yes
    Output TypeBoth LVDS, CMOS CMOS LVDS Both LVDS, CMOS
    Input Voltage Swing (Max)2.3 Volt 1.19 Volt 1.2 Volt 2.4 Volt
    INL (+/-)23 LSB 0.9 LSB 0.8 LSB 23 LSB
    PGA Gain Resolution8 bits 9 bits 9 bits 8 bits
    PGA Gain (Min)-4.2 dB 0 dB 0 dB -3 dB
    PGA Gain (Max)18.4 dB 26 dB 26 dB 17.9 dB
    DAC Offset Resolution (+/-)9 bits 14 bits 14 bits 9 bits
    DAC Offset Range (+/-)307 mV 337 mV 340 mV 600 mV
    Supply Voltage3.3 Volt 3.3 Volt 3.3 Volt 3.3 Volt
    Power Dissipation0.755 Watt 1.04 Watt 1.02 Watt 0.505 Watt
    Part Number(s)
    (NSID)    		Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM98725CCMT/NOPB


    RoHS Status

    TSSOP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    DIGI-KEYWorldwide78
    MOUSERWorldwide34
    		$15.00 each at 100+ pcsrail
    of
    34
    LM98725CCMTX/NOPB


    RoHS Status

    TSSOP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$15.00 each at 100+ pcsreel
    of
    1000

    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM98725.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM98725 is located at RoHS Status.

    Part Number(s)
    (NSID)    		Weight
    (milligrams)    		TypePinsMSL RatingPeak ReflowRoHS
    Status    		CAD SymbolsModelsPackage
    Marking
    Format
    LM98725CCMT/NOPB

    		222.11
    		TSSOP562260DetailDownload
    ibis file    		NSUZXYTTE#
    LM98725CCMT
    LM98725CCMTX/NOPB

    		222.11
    		TSSOP562260DetailDownload
    ibis file    		NSUZXYTTE#
    LM98725CCMT

    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM98725.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM98725 is located at RoHS Status.

    CAD Symbols and Models
    Download LM98725 CAD Symbols
    		 Models

    ibis file


    [Information as of 9-Feb-2012]
    Copyright © 2011 National Semiconductor Corporation