High-performance CVBS/S-video reconstruction filter and buffer supports all SDTV video formats

Maxim Integrated Products’ MAX7453 is a high-performance, three-channel video reconstruction filter and buffer for Y/C (S-video) and CVBS video signal applications. Supporting all SDTV video formats, this device enables designers to turn two system-on-a-chip DAC outputs into three video outputs. To reconstruct the DAC output, each channel integrates a lowpass filter and video buffer capable of driving one or two standard 150 ohm video loads with a 2Vp-p signal into either an AC- or DC-coupled load. The Y and C video inputs are summed by the CVBS summer to produce a composite video output. Optimized for NTSC and PAL SDTV video systems, the MAX7453 is ideal for DAC-reconstruction digital video applications, such as set-top boxes (STBs), personal video recorders (PVRs), hard-disk recorders (HDRs), and DVD players.

Many STB and DVD applications require an ideal filter response to achieve high-quality video images and to filter out unwanted DAC artifacts. To meet these requirements, the MAX7453 provides a maximally flat frequency response, a 42dB stopband attenuation at 27MHz, and +6dB output buffers that are capable of driving 150 ohm loads on each channel. Additionally, the output buffers can drive either an AC or a DC load such that the blanking-level voltage after the backmatch resistor is less than 1V. This feature eliminates the need for costly, bulky output capacitors in designs that utilize DC-coupled outputs.

Maxim Integrated Products