ADI ADA4424-6 六路SD-ED-HD视频滤波方案

ADI 公司的ADA4424-6是六路带有电荷泵的SD/ED/HD视频滤波器,包括有用于标清(SD)的连个5阶Butterworth滤波器,用于高清(HD)的三个5阶滤波器.滤波器/缓冲器的工作电压3.3V,完全支持(EIAJ RC-5237 D5和S1/S1所提供的信令,而模拟部分工作电压5V.本文介绍了ADA4424-6的主要特性,功能方框图以及自动失调消除模式的ADA4424-6应用框图.

6-Channel SD/ED/HD Video Filter with Charge Pump

The ADA4424-6 is a high performance video reconstruction filter specifically designed for consumer applications. It consists of a standard definition (SD) section with two fifth-order Butterworth filters, and a high definition (HD) section with three fifth-order filters. The SD section contains an internal Y/C summer for CVBS output, whereas the HD section provides selectable corner frequencies for either extended definition (ED) or high definition (HD) signals. The ADA4424-6 filter/buffer section operates from a single 3.3 V supply. Full support for D-terminal (EIAJ RC-5237 D5) and S1/S2 signaling is provided, along with a dedicated 5 V supply pin. Separate enable pins are provided for the SD and HD sections.

The luma channels (Y_IN, HY_IN) of the ADA4424-6 are capable of detecting and cancelling dc input offsets of up to 1.1 V. Four distinct modes of detection/cancellation are available. The output drivers on the ADA4424-6 feature rail-to-rail outputs with 6.2 dB gain. An on-board charge pump allows the outputs to swing up to 1.4 V below ground, eliminating the need for large coupling capacitors. Each output is capable of driving two 75 Ω doubly terminated cables.

The ADA4424-6 is available in a 38-lead TSSOP and operates in the extended industrial temperature range of −40℃ to +85℃.

图1.ADA4424-6功能方框图

图2.自动失调消除模式的ADA4424-6应用框图