REV. A

–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

AD9945

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