AD9974BBCZ datasheet(14/52 Pages) AD

14 / 52 page

AD9974

Rev. A | Page 14 of 52

THEORY OF OPERATION

CCD

SERIAL

INTERFACE

DOUT_A

DOUT_B

DIGITAL IMAGE

PROCESSING

ASIC

V DRIVER

HD_A, VD_A,

HD_B, VD_B

CLI_A, CLI_B

V1 > Vx, VSG1 > VSGx, SUBCK

H1_A TO H4_A, RG_A

H1_B TO H4_B, RG_B

AD9974

INTEGRATED

AFE + TD

CCDINP_A

CCDINM_A

CCDINP_B

CCDINM_B

Figure 14. Typical Application

Figure 14 shows the typical system block diagram for the AD9974.

The charge-coupled device (CCD) output is processed by the

analog front-end (AFE) circuitry of the AD9974, consisting of a

CDS, VGA, black level clamp, and ADC. The digitized pixel

information is sent to the digital image processor chip, which

performs the postprocessing and compression. To operate the

CCD, all CCD timing parameters are programmed into the

AD9974 from the system ASIC through the 3-wire serial

interface. From the system master clock, CLI_X, which is provided

by the image processor or external crystal, the AD9974 generates

the horizontal clocks of the CCD and all internal AFE clocks.

All AD9974 clocks are synchronized with VD and HD inputs.

All of the AD9974 horizontal pulses (CLPOB, PBLK, and

HBLK) are programmed and generated internally.

The H-drivers for H1 to H4 and RG are included in the

AD9974, allowing these clocks to be directly connected to the

CCD. An H-driver voltage of 3 V is supported in the AD9974.

Figure 15 and Figure 16 show the maximum horizontal and

vertical counter dimensions for the AD9974. All internal horizontal

and vertical clocking is controlled by these counters, which specify

line and pixel locations. Maximum HD length is 8191 pixels per

line, and maximum VD length is 8191 lines per field.

13-BIT HORIZONTAL = 8192 PIXELS MAX

13-BIT VERTICAL = 8192 LINES MAX

MAXIMUM COUNTER DIMENSIONS

Figure 15. Vertical and Horizontal Counters

MAX VD LENGTH IS 8192 LINES

CLI

MAX HD LENGTH IS 8192 PIXELS

Figure 16. Maximum VD/HD Dimensions

AD9974BBCZ датащи(PDF) 14 Page - Analog Devices

AD9974BBCZ датащи(HTML) 14 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

датащи скачать

ссылки URL