4-Channel Video Reconstruction Filter

The MAX7445 4-channel, buffered video reconstruction filter is ideal for anti-aliasing and DAC-smoothing video applications or wherever analog video is reconstructed from a digital data stream (such as cable/satellite/terrestrial set-top boxes, DVD players, hard-disk recorders (HDRs), and personal video recorders (PVRs)). This device operates from a single +5V supply and has a flat passband out to 5MHz with a stopband attenuation of 43dB at 27MHz. This makes it ideal for use with NTSC, PAL, and standard-definition digital TV (SDTV) video systems. Each output is capable of driving two standard 150Ω video loads.

The MAX7445 has three modes of operation. Mode 1 processes CVBS and RGB video signals. Mode 2 processes CVBS, Y, and C signals, as well as a second asynchronous CVBS video signal. Mode 3 processes RGB and CVBS (asynchronous) video signals. An external pin adjusts the gain of the video buffer to either +6dB, +9.5dB, or +12dB to accommodate video-encoder DAC output signals of < 1V. High-frequency boost circuitry provides picture sharpness with +1.2dB of gain boost without degradation in the stopband. The output video drivers can be disabled with an external pin.

The MAX7445 is available in a 14-pin TSSOP package with an exposed pad, and is specified over the -40°C to +85°C extended temperature range.

Applications

* Desktop Video Editors * Digital VCRs * DVD Players * Game Consoles * Set-Top Boxes/HDRs

* 4-Channel Filter and Buffer for CVBS, RGB, or Y/C Video Signals

* Filter Response Ideal for NTSC, PAL, and Interlaced SDTV Video Signals

* 43dB (typ) Stopband Attenuation at 27MHz

* ±0.75dB (max) Passband Ripple Out to 5MHz

* Blanking Level Voltage on Cable < 1V

* Each Channel Drives Two 150Ω Video Loads

* +5V Single-Supply Voltage

* Selectable Gain: +6dB, +9.5dB, and +12dB

* Small 14-Pin TSSOP Package