TW9900

The TW9900 is a low power NTSC/PAL/SECAM video decoder chip that is designed for portable applications. It consumes less than 100mW in typical composite input applications. The available power-down mode further reduces the power consumption. It uses the 1. 8V for both analog and digital supply voltage and 3. 3V for I/O power. A single 27MHz crystal is all that is needed to decode all analog video standards. The video decoder decodes the baseband analog CVBS or S-video signals 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 SECAM) and synchronization circuitry. The Y/C separation is done with high quality adaptive 4H comb filter for reduced cross color and cross luminance. The advanced synchronization processing circuitry can produce stable pictures for a non-standard signal as well as a weak signal. The output of the decoder is line-locked and formatted to the ITU-R 656 output with embedded sync. The TW9900 also includes circuits to detect and process vertical blanking interval (VBI) signal. It slices and processes VBI data for output through video bus. Some information can also be alternatively retrieved through the host interface. It also detects copy-protected signal according to Macrovision standard including AGC and color stripe pulses. A 2-wire serial host interface is used to simplify system integration. All the functions can be controlled through this interface.