Complete 12-Bit 30 MSPS
CCD Signal Processor
a
AD9845A
PRODUCT DESCRIPTION
FEATURES
The AD9845A is a complete analog signal processor for CCD
applications. It features a 30 MHz single-channel architecture
designed to sample and condition the outputs of interlaced and
progressive scan area CCD arrays. The AD9845A’s signal chain
consists of an input clamp, correlated double sampler (CDS),
Pixel Gain Amplifier (PxGA), digitally controlled variable gain
amplifier (VGA), black level clamp, and a 12-bit A/D converter.
Additional input modes are provided for processing analog
video signals.
30 MSPS Correlated Double Sampler (CDS)
4 dB ꢀ 6 dB 6-Bit Pixel Gain Amplifier (PxGA®)
2 dB to 36 dB 10-Bit Variable Gain Amplifier (VGA)
Low Noise Clamp Circuits
Analog Preblanking Function
12-Bit 30 MSPS A/D Converter
Auxiliary Inputs with VGA and Input Clamp
3-Wire Serial Digital Interface
3 V Single Supply Operation
Low Power: 140 mW @ 3 V Supply
48-Lead LQFP Package
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.
APPLICATIONS
Digital Still Cameras
Digital Video Camcorders
Industrial Imaging
The AD9845A operates from a single 3 V power supply, typi-
cally dissipates 140 mW, and is packaged in a 48-lead LQFP.
FUNCTIONAL BLOCK DIAGRAM
HD
VD
PBLK
AVDD
AVSS
CLPOB
CLP
COLOR
STEERING
DRVDD
DRVSS
4dB ꢀ 6dB
2dB~36dB
VGA
CDS
PxGA
CCDIN
12
2:1
MUX
ADC
DOUT
CLP
6
VRT
VRB
BANDGAP
REFERENCE
CLPDM
AUX1IN
OFFSET
DAC
10
2:1
MUX
BUF
INTERNAL
BIAS
CML
AUX2IN
8
CONTROL
REGISTERS
CLP
DVDD
DVSS
DIGITAL
INTERFACE
INTERNAL
TIMING
AD9845A
SHP
SHD DATACLK
SL
SCK
SDATA
PxGA is a registered trademark of Analog Devices, Inc.
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
Fax: 781/326-8703
World Wide Web Site: http://www.analog.com
© Analog Devices, Inc., 2001