REV. 0

AD9845A

–20–

CCD

CCDIN

BUFFER

0.1 F

AD9845A

REGISTER

DATA

SERIAL

INTERFACE

DIGITAL

OUTPUTS

DIGITAL IMAGE

PROCESSING

ASIC

TIMING

GENERATOR

V-DRIVE

CCD

TIMING

CDS/CLAMP

TIMING

Figure 32. System Applications Diagram

APPLICATIONS INFORMATION

The AD9845A is a complete Analog Front End (AFE) product

for digital still camera and camcorder applications. As shown in

Figure 32, the CCD image (pixel) data is buffered and sent to

the AD9845A analog input through a series input capacitor.

The AD9845A performs the dc restoration, CDS, gain adjust-

ment, black level correction, and analog-to-digital conversion.

The AD9845A’s digital output data is then processed by the

image processing ASIC. The internal registers of the AD984x—

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.