Datasheet

–12–
AD9945
APPLICATIONS INFORMATION
The AD9945 is a complete analog front end (AFE) product for
digital still camera and camcorder applications. As shown in
Figure 10, the CCD image (pixel) data is buffered and sent to the
AD9945 analog input through a series input capacitor. The
AD9945 performs the dc restoration, CDS, gain adjustment, black
level correction, and analog-to-digital conversion. The AD9945’s
digital output data is then processed by the image processing
ASIC. The internal registers of the AD9945—used to control
gain, offset level, and other functions—are programmed by the
ASIC or microprocessor through a 3-wire serial digital interface.
A system timing generator provides the clock signals for both the
CCD and the AFE.
CCD
CCDIN
BUFFER
V
OUT
AD9945
ADC
OUT
REGISTER-
DATA
SERIAL
INTERFACE
DIGITAL
OUTPUTS
DIGITAL IMAGE
PROCESSING
ASIC
TIMING
GENERATOR
V-DRIVE
CCD
TIMING
CDS/CLAMP
TIMING
0.1␮F
Figure 10. System Applications Diagram
REV.
C