AD9945 Datasheet, PDF (1/16 Pages) Analog Devices – Complete 12-Bit 40 MHz CCD Signal Processor

FEATURES
40 MSPS Correlated Double Sampler (CDS)
6 dB to 40 dB 10-Bit Variable Gain Amplifier (VGA)
Low Noise Optical Black Clamp Circuit
Preblanking Function
12-Bit 40 MSPS A/D Converter
No Missing Codes Guaranteed
3-Wire Serial Digital Interface
3 V Single-Supply Operation
Low Power: 140 mW @ 3 V Supply
Space-Saving 32-Lead 5 mm ؋ 5 mm LFCSP
APPLICATIONS
Digital Still Cameras
Digital Video Camcorders
PC Cameras
Portable CCD Imaging Devices
CCTV Cameras
Complete 12-Bit 40 MHz
CCD Signal Processor
AD9945
GENERAL DESCRIPTION
The AD9945 is a complete analog signal processor for CCD
applications. It features a 40 MHz single-channel architecture
designed to sample and condition the outputs of interlaced and
progressive scan area CCD arrays. The AD9945’s signal chain
consists of a correlated double sampler (CDS), a digitally con-
trolled variable gain amplifier (VGA), a black level clamp, and a
12-bit A/D converter.
The internal registers are programmed through a 3-wire serial digital
interface. Programmable features include gain adjustment, black
level adjustment, input clock polarity, and power-down modes.
The AD9945 operates from a single 3 V power supply, typi-
cally dissipates 140 mW, and is packaged in a space-saving
32-lead LFCSP.
FUNCTIONAL BLOCK DIAGRAM
REFT REFB
PBLK
AD9945
CCDIN
CDS
6dB TO 40dB
VGA
BAND GAP
REFERENCE
12-BIT
ADC
DRVDD
DRVSS
12
DOUT
AVDD
AVSS
10
CONTROL
REGISTERS
DIGITAL
INTERFACE
CLP
CLPOB
INTERNAL
TIMING
DVDD
DVSS
SL
SCK SDATA
SHP SHD DATACLK
REV. A
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