Video switch suits SCART STBs

Maxim Integrated Products introduced the MAX7457, a four-channel video switch. It filters and buffers CVBS, R, G and B video signals, which is said to makes it suitable for European dual SCART set-top boxes (STBs) with a VCR loop-through. According to Maxim, using their video switch saves 50 percent in cost than using integrated A/V switching devices.

The product is used in anti-aliasing and DAC-smoothing video applications or when analog video is reconstructed from a digital data stream, such as cable/satellite/terrestrial STBs, DVD players, hard disk recorders and personal video recorders. The device uses a continuous-time, Butterworth-type response low-pass filter to attenuate the sampling frequency of the DAC encoder. All video signal-timing extraction and clamping are done within the device.

The MAX7457 operates from a single 5V supply and has a flat passband out to 5MHz, suitable for PAL video signals with a stopband of 43dB at 27MHz. The output buffer has a fixed gain of 6dB capable of driving two standard video loads with a 2V_p-p signal. Output disable control is also through an external pin. The MAX7457 is available in the extended (-40°C to 85°C) temperature range, with prices starting at $1.62 in quantities of 1,000 and up.