Multi-Standard, Triple Consumer video amps

17th September 2007

ES Admin

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Texas Instruments has introduced a family of flexible three-channel integrated video buffers optimized for consumer video applications where performance, space savings and lower system cost are required. The family supports HDTV, SDTV and a variety of digital media processors, such as TI’s DaVinci processors. The amplifiers incorporate a fifth-order Butterworth filter, which can be used as an encoder’s digital-to-analog converter (DAC) reconstruction filter. The devices provide video buffering by rejecting DAC images for better video quality in consumer applications such as set-top boxes, USB-powered video, portable video recorders and other video applications.

The THS7314, THS7315 and THS7316 offer design flexibility as the inputs can be configured for either AC- or DC-coupled applications. In addition, unlike typical solutions, the family can support a single 3-V to 5-V supply, eliminating the need for a separate 5-V supply. The devices’ rail-to-rail output allows AC- or DC-output coupling so that designers can use 3.3-V supply without headroom issues. The ability for each channel to drive two video lines, or 75-ohms loading, allows for maximum flexibility as a video line driver.

Each device addresses requirements of today’s video standards. The amplifiers incorporate output level shift, which allows for a full sync dynamic range at the output with 0-V input. The AC-coupled modes include a transparent sync-tip clamp option for CVBS, Y', and G'B'R' signals with bottom-level sync. AC-coupled biasing for C'/P'b/P'r channels can easily be achieved by adding an external resistor to Vs+ (voltage supply pin).

The THS7314 and THS7315 are well-suited for SDTV and support CVBS, S-Video, Y'U'V and Y'P'bP'r 480i/576i. The THS7314 has a typical 6-dB output gain while the THS7315 has a 14.3-db fixed gain, which enables it to work well with TI’s DaVinci and OMAPTM processors. The THS7316 supports Y'P'bP'r 720p/1080i/up to 1080p30 and G'B'R' (R'G'B') standards for HDTV with a 6-dB output gain.