LM98725 - Three Channel, 16-Bit, 81 MSPS Analog Front End with LVDS/CMOS Output and Integrated CCD/CIS Sensor Timing Generator
Datasheet Packaging Samples & Pricing Models Knowledge Base

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

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)

General 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. More...


Applications


Multi-Function Peripherals
High-speed Currency/Check Scanners
Flatbed or Handheld Color Scanners
High-speed Document Scanners
  Typical Application
click for larger image

Typical Application

ParametersValues
Input Channels 3
ADC Sampling Rate 81 MSPS
Channel Sampling Rate (MSPS) 3 to 30
ADC Resolution 16 bits
Input Signal Polarity Both Pos, Neg
Input Sampler Type Both SH, CDS
Integrated Timing Generator Yes
Output Type Both LVDS, CMOS
Input Voltage Swing (Max) 2.3 Volt
INL (+/-) 23 LSB
Noise Floor -76 dB
PGA Gain Resolution 8 bits
PGA Gain (Min) -4.2 dB
PGA Gain (Max) 18.4 dB
DAC Offset Resolution (+/-) 9 bits
DAC Offset Range (+/-) 307 mV
Supply Voltage 3.3 Volt
Power Dissipation 0.755 Watt

  Also Recommended
LM98519For A 6-channel AFE, With CMOS Outputs
LM98620For A 6-channel AFE, With LVDS Outputs
LM98714For A Lower-Speed Part With Fewer Features
Block Diagram
click for larger image

System Block Diagram

Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM98725 3 Channel, 16-Bit, 81 MSPS Analog Front End with LVDS/CMOS Output, Integrated CCD/CIS Sensor Timing Generator and Spread Spectrum Clock Generation 464
Kbytes
24-Sep-09 Download

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Package Availability, Models, Samples & Pricing
Part NumberPackageFactory Lead TimeModelsSamples &
Electronic
Orders
Budgetary PricingStd
Pack
Size
Package
Marking
Format
TypePinsSpec.MSL
Rating
Peak
Reflow
RoHS
Report
CAD
Symbols
WeeksQtyQty$US each
LM98725CCMTTSSOP56NOPB2260RoHS N/A Full production
LM98725.ibs
Samples
Buy Now
100+$15.00rail
of
34
NSUZXYTTE#
LM98725CCMT
6 weeksN/A
LM98725CCMTXTSSOP56NOPB2260RoHS N/A Full production
LM98725.ibs
 
Buy Now
100+$15.00reel
of
1000
NSUZXYTTE#
LM98725CCMT
6 weeksN/A

General 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.

[Information as of 7-Nov-2009]