a
Complete 10-Bit 20 MSPS
CCD Signal Processor
AD9843A
PRODUCT DESCRIPTION
FEATURES
20 MSPS Correlated Double Sampler (CDS)
4 dB ؎ 6 dB Variable CDS Gain with 6-Bit Resolution
2 dB to 36 dB 10-Bit Variable Gain Amplifier (VGA)
Low Noise Clamp Circuits
Analog Preblanking Function
10-Bit 20 MSPS A/D Converter
Auxiliary Inputs with VGA and Input Clamp
3-Wire Serial Digital Interface
3 V Single Supply Operation
Low Power: 65 mW @ 2.7 V Supply
48-Lead LQFP Package
The AD9843A is a complete analog signal processor for CCD
applications. It features a 20 MHz single-channel architecture
designed to sample and condition the outputs of interlaced and
progressive scan area CCD arrays. The AD9843A’s signal chain
consists of an input clamp, correlated double sampler (CDS),
digitally controlled variable gain amplifier (VGA), black level
clamp, and 10-bit A/D converter. Additional input modes are
provided for processing analog video signals.
The internal registers are programmed through a 3-wire serial
digital interface. Programmable features include gain adjustment, black level adjustment, input configuration, and powerdown modes.
APPLICATIONS
Digital Still Cameras
Digital Video Camcorders
PC Cameras
The AD9843A operates from a single 3 V power supply, typically dissipates 78 mW, and is packaged in a 48-lead LQFP.
FUNCTIONAL BLOCK DIAGRAM
PBLK
AVDD
CLPOB
AVSS
DRVDD
CLP
4dB؎6dB
DRVSS
2dB~36dB
CDS
CCDIN
2:1
MUX
10
10-BIT
ADC
VGA
DOUT
CLP
CLPDM
10
AUX1IN
2:1
MUX
BUF
8
VRB
INTERNAL
BIAS
6
AUX2IN
VRT
BANDGAP
REFERENCE
OFFSET
DAC
CML
INTERNAL
REGISTERS
CLP
DVDD
DIGITAL
INTERFACE
AD9843A
SL
SCK
INTERNAL
TIMING
SDATA
SHP
SHD
DVSS
DATACLK
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2000
