4-CH WD1 (960H)/D1 Compatible Video Decoders and Audio Codecs

The TW2984 is a low power NTSC/PAL video decoder chip that is designed for video surveillance applications. It consumes very low power in a typical composite input application. The available power down mode further reduces the power consumption. It uses the 1. 0V for digital supply voltage and 3. 3V for I/O and analog power. A single 27MHz crystal is all that needed to decode all analog video standards. The video decoder decodes the base-band analog CVBS into digital 8-bit 4:2:2 YCbCr for output. It consists of analog front-end with input source selection, variable gain amplifier and analog-to-digital converters, Y/C separation circuit, multi-standard color decoder (PAL BGHI, PAL M, PAL N, combination PAL N, NTSC M, NTSC 4. 43) and synchronization circuitry. The Y/C separation is done with high quality adaptive 4H (5-line) comb filter for reduced cross color and cross luminance. The advanced synchronization processing circuitry can produce stable pictures for non-standard signal as well as weak signal.