AD9844A Datasheet, PDF (1/16 Pages) Analog Devices – Complete 12-Bit 20 MSPS CCD Signal Processor

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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
12-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
APPLICATIONS
Digital Still Cameras
Digital Video Camcorders
PC Cameras
Complete 12-Bit 20 MSPS
CCD Signal Processor
AD9844A
PRODUCT DESCRIPTION
The AD9844A 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 AD9844A’s signal chain
consists of an input clamp, correlated double sampler (CDS),
digitally controlled variable gain amplifier (VGA), black level
clamp, and 12-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 power-down
modes.
The AD9844A operates from a single 3 V power supply, typi-
cally dissipates 78 mW, and is packaged in a 48-lead LQFP.
CCDIN
CLPDM
AUX1IN
AUX2IN
PBLK
FUNCTIONAL BLOCK DIAGRAM
AVDD
AVSS
CLPOB
4dB؎6dB
CDS
CLP
2:1
MUX
BUF
CLP
AD9844A
2:1
MUX
2dB~36dB
VGA
CLP
12-BIT
12
ADC
10
6
INTERNAL
REGISTERS
OFFSET
DAC
8
BANDGAP
REFERENCE
INTERNAL
BIAS
DIGITAL
INTERFACE
INTERNAL
TIMING
DRVDD
DRVSS
DOUT
VRT
VRB
CML
DVDD
DVSS
SL
SCK SDATA
SHP SHD DATACLK
REV. 0
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© Analog Devices, Inc., 2000