bt829bkrf ETC-unknow, bt829bkrf Datasheet - Page 57

• Manufacturer Part Number: bt829bkrf
• Description: Video Streamii Decoders
• Manufacturer: ETC-unknow

Bt829B/827B
VideoStream II Decoders
2.1.7 Automatic Gain Controls (AGC)
The REFOUT, CREF+, and YREF+ pins should be connected together as shown
in Figure 2-1. In this configuration, the Bt829B controls the voltage for the top of
the reference ladder for each A/D. The automatic gain control adjusts the YREF+
and CREF+ voltage levels until the back porch of the Y-video input generates a
digital code 0x38 from the A/D. If the video being digitized has a non-standard
sync height to video height ratio, the digital code used for AGC may be changed
by programming the ADC Interface Register (0x1A). Figure 2-2 illustrates
Bt829B external circuitry with reduced passive components.
D829BDSA
2.0 Electrical Interfaces
2.1 Input Interface
47