CS7615 datasheet(10/36 Pages) CIRRUS

10 / 36 page

CS7615

DS231PP6

ternal analog gain range is 38 dB in steps of

0.078 dB ideal. Adjustments made in these small

steps should cause no noticeable brightness change

in the image from frame to frame. In addition to the

internal analog gain, the control loop will vary the

shutter speed through the OFDX output from 0 to -

54 dB as it deems necessary.

The AGC algorithm uses a luma or mosaic histo-

gramming technique in which the brightness of

each pixel is binned into one of seven bins. The

number of pixels in a bin will produce an error sig-

nal that is then used to update the gain. The follow-

ing parameters control the loop dynamics and are

programmable to meet the needs of the user.

PAL bit: Selects a PAL or NTSC camera sys-

tem.

AGC Window: Adjusts what portion of the

frame is used for the AGC algorithm.

Luma/Mosaic: Selects whether luma or mosaic

data are used in the histogramming.

HREF

HSYNC

CLAMP

HENB

CCD

OUTPUT

HBPD

Active Video

Hsnyr

Hsynf

Hstart

Hend

Optical

black pixels

Inactive

video

Active video

Hlen

Figure 9. Timing Diagram for Href, HSYNC, Clamp, and Henb

CS7615 Datasheet(PDF) 10 Page - Cirrus Logic