DATASHEET
TW2851
4-Channel A/V Decoder with Multiplexer/VGA/LCD
Display Processor for Security Applications
The TW2851 is a fully integrated A/V decoder,
multiplexer, and display processor chip. It has eight
CVBS analog inputs fed into four internal high
quality NTSC/PAL video decoders. It has four digital
input ports supporting various type of input format,
including four BT 656 inputs, two BT 601 inputs, or
one 1120 playback input. It has one optional VGA
display controller or LCD panel controller, two CVBS
display, one digital SPOT output, two digital
recorder outputs, and one digital display output.
Every output has its associated graphic overlay
function that displays bitmap for OSG, single box,
2D array box, borders, privacy mask, and mouse
cursor.
The four built-in video decoders include four antialiasing filters, 10bit Analog-to-Digital converters,
proprietary digital gain/clamp controller, and high
quality Y/C separator to reduce cross-noise.
Associated with each video decoder, there are builtin motion, blind, and night detectors to provide
alarm signals, a noise reducer to reduce the …