REV. A

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a

AD9826

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 2001

Complete 16-Bit Imaging

Signal Processor

FUNCTIONAL BLOCK DIAGRAM

OEB

DOUT

SCLK

SLOAD

SDATA

ADCCLK

CDSCLK2

CDSCLK1

OFFSET

VINB

VING

VINR

AVDD

AVSS

CML

CAPT

AVDD

AVSS

BANDGAP

REFERENCE

AD9826

DRVDD

DRVSS

GAIN

REGISTERS

OFFSET

REGISTERS

3:1

MUX

16:8

MUX

16-BIT

ADC

DIGITAL

CONTROL

INTERFACE

CONFIGURATION

REGISTER

RED

GREEN

BLUE

MUX

REGISTER

8

16

RED

GREEN

BLUE

PGA

6

9

PGA

PGA

CDS

9-BIT

DAC

CDS

9-BIT

DAC

CDS

9-BIT

DAC

INPUT

CLAMP

BIAS

CAPB

FEATURES

16-Bit 15 MSPS A/D Converter

3-Channel 16-Bit Operation up to 15 MSPS

1-Channel 16-Bit Operation up to 12.5 MSPS

2-Channel Mode for Mono Sensors with Odd/Even Outputs

Correlated Double Sampling

1~6

Programmable Gain

300 mV Programmable Offset

Input Clamp Circuitry

Internal Voltage Reference

Multiplexed Byte-Wide Output

Optional Single Byte Output Mode

3-Wire Serial Digital Interface

3 V/5 V Digital I/O Compatibility

28-Lead SSOP Package

Low Power CMOS: 400 mW (Typ)

Power-Down Mode Available

APPLICATIONS

Flatbed Document Scanners

Digital Copier

Multifunction Peripherals

Infrared Imaging Applications

Machine Vision

PRODUCT DESCRIPTION

The AD9826 is a complete analog signal processor for imaging

applications. It features a 3-channel architecture designed to

sample and condition the outputs of trilinear color CCD arrays.

Each channel consists of an input clamp, Correlated Double

Sampler (CDS), offset DAC, and Programmable Gain Amplifier

(PGA), multiplexed to a high-performance 16-bit A/D converter.

The AD9826 can operate at speeds greater than 15 MSPS with

reduced performance.

The CDS amplifiers may be disabled for use with sensors that

do not require CDS, such as Contact Image Sensors (CIS),

CMOS active pixel sensors, and Focal Plane Arrays.

The 16-bit digital output is multiplexed into an 8-bit output word,

which is accessed using two read cycles. There is an optional

single byte output mode. The internal registers are programmed

through a 3-wire serial interface, and provide adjustment of

the gain, offset, and operating mode.

The AD9826 operates from a single 5 V power supply, typically

consumes 400 mW of power, and is packaged in a 28-lead SSOP.