CONEX BT861, BT860 Datasheet

Digital Video Encoder

Bt860/861

digital infotainment products

• Six 10-bit DACs with individual
power management

• Simultaneous output of RGB, S-video
and CVBS, or YUV, S-video and CVBS

• Current drive output DACs for superior
video quality and reduced system cost

• Four output sharpness filtering options
(0, 1, 2, 3.5 dB gain)

• Programmable adjustment of brightness,
contrast, color saturation and hue

Distinguishing Features

High-Performance Multisource Video
for a Wide Range of Systems

Conexant’s Bt860 and Bt861 are multiport digital video encoders
with pixel synchronization and per-pixel blending capabilities.
The three 8-bit YCrCb data ports allow for a variety of video
and graphics overlay configurations useful in video set-top box
applications. The Bt860/861 is designed specifically for video
systems requiring the generation of simultaneous composite,
S-video (Y/C) and either component YUV or RGB (SCART)
video signals.

High-performance video combined with the right set of features
make the Bt860/861 a versatile device for almost any video
system. 10-bit DACs provide the clear, lifelike video required for
modern satellite and cable television set-top boxes, Super VCD
and DVD players, PC add-in cards, video conferencing systems
and digital cameras. Several power conservation modes extend
portable system battery life and help reduce system heating.
New televisions and media which make use of wide screen 16:9
aspect ratios are also supported by the Bt860/861 to provide the
best flexibility, performance and functionality.

Digital Video Encoder

Bt860/861

digital infotainment products

Multisource video is a key feature of the Bt860/861. The
primary video port (P) is designed to accept both digital
video and graphics overlay content from an MPEG video
decoder or OSD ICs. This input stream can be either ITU-R
BT.601 or 656 in format — as is typically generated by
MPEG decoder ICs. The second video port (VID) will
accept an alternate digital video stream from a video
decoder, such as Conexant’s Video Stream family of
devices. The third port (OSD) may be used for dedicated
graphics overlay devices, such as providing a higher­quality user interface or superior on-screen titles.
Alternatively, a second MPEG decoded stream could
also be the input to the OSD port for use with multiple
MPEG decoder ICs. A pixel synchronization mechanism
ensures proper timing between the three ports to
deliver the highest-video quality.

The block diagram below illustrates an example of
how the Bt860/861 may be used in a TV set-top box,
DVD player, or PC card. The white boxes represent

the typically used components. The light gray shaded
box represents the optional components used for video
capture. The medium grey shaded box represents the
optional graphic processor IC, which may be added for
enhanced OSD or superior user interface.

Worldwide Standards Supported

Worldwide video standards are supported, including
NTSC-M (North America, Taiwan, Japan), PAL-B,D,G,H,I
(Europe, Asia), PAL-M (Brazil), PAL-N (Uruguay,
Paraguay), PAL-Nc (Argentina), PAL-60, and SECAM.
The Bt860 and Bt861 are pin and functionally
identical, except the Bt861 also contains Macrovision

7.X copy protection circuitry used in DVD players
and TV set-top boxes. This permits all types of video
systems to use the Bt860/861 and achieve truly high­performance video.

Bt860/861 functional block diagram

Typical system functional block diagram