NSC LM98714CCMT, LM98714 Datasheet

LM98714
Three Channel, 16-Bit, 45 MSPS Digital Copier Analog
Front End with Integrated CCD/CIS Sensor Timing
Generator and LVDS Output

General Description

The LM98714 is a fully integrated, high performance 16-Bit,
45 MSPS signal processing solution for digital color copiers,
scanners, and other image processing applications. High­speed 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 Contact Image Sensors and 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 inputs. The signals are then routed to a 45MHz
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
LM98714 transparent in the image reproduction chain.

Applications

n Multi-Function Peripherals
n Facsimile Equipment
n Flatbed or Handheld Color Scanners
n High-speed Document Scanner

Features

n LVDS/CMOS Outputs
n LVDS/CMOS Pixel Rate Input Clock or ADC Input Clock
n CDS or S/H Processing for CCD or CIS sensors

n Independent Gain/Offset Correction for Each Channel
n Digital Black Level Correction Loop for Each Channel
n Programmable Input Clamp Voltage
n Flexible CCD/CIS Sensor Timing Generator

Key Specifications

n Maximum Input Level 1.2 or 2.4 Volt Modes
n (both with + or - polarity option)
n ADC Resolution 16-Bit
n ADC Sampling Rate 45 MSPS
n INL +/- 23 LSB (typ)
n Channel Sampling Rate 15/22.5/30 MSPS
n PGA Gain Steps 256 Steps
n PGA Gain Range 0.7 to 7.84x
n Analog DAC Resolution +/-9 Bits
n Analog DAC Range +/-300mV or +/-600mV
n Digital DAC Resolution +/-6 Bits
n Digital DAC Range -1024 LSB to + 1008 LSB
n SNR -74dB (

@

0dB PGA Gain)

n Power Dissipation 505mW (LVDS) 610mW (CMOS)
n Operating Temp 0 to 70˚C
n Supply Voltage 3.3V Nominal (3.0V to 3.6V range)

System Block Diagram

20105370

October 2006

LM98714 - Three Channel, 16-Bit, 45 MSPS Digital Copier Analog Front End with Integrated

CCD/CIS Sensor Timing Generator and LVDS Output

© 2006 National Semiconductor Corporation DS201053 www.national.com

LM98714 Overall Chip Block Diagram

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FIGURE 1. Chip Block Diagram

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LM98714 Pin Out Diagram

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FIGURE 2. LM98714 Pin Out Diagram

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Typical Application Diagram

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FIGURE 3. Typical Application Diagram

LM98714

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