Video filter features group delay predistortion

The FMS6406 is billed as the industry's most highly integrated standard definition, lowpass reconstruction video filter/driver for set-top box and personal video recorder applications.

New from Fairchild Semiconductor, the FMS6406 is billed as the industry's most highly integrated standard definition, lowpass reconstruction video filter/driver for set-top box and personal video recorder (PVR) applications.

This FMS6406 features an integrated sound notch and output drivers that meet the latest cable and satellite set-top box performance requirements of 170ns group delay predistortion.

The device compensates for the inherent distortion in the TV receiver by including a group delay and chroma-luma delay FCC predistortion circuit that prevents the image's high-frequency edges from appearing distorted on the TV screen.

The notch filter creates a window in the video signal at approximately 4.5MHz to eliminate interference between the audio and video before these signals are combined in the channel 3/4 RF modulator.

"Fairchild's highly integrated video filter reduces board space by 30 to 40% by effectively replacing discrete reconstruction filters, an external sound notch and group delay compensation circuits and cable drivers, while increasing system reliability in set-top box and PVR applications".

"This integration translates into significant board savings", says Jeremy Tole, Fairchild's Technical Marketing Manager, Video Products.

"The FMS6406 answers a pressing need in the set-top box and PVR market by providing a highly efficient and inherently low-cost system solution".

Fairchild's FMS6406, a 5th order video filter, eliminates unwanted digital artefacts by significantly reducing the clock and image frequencies after the digital-to-analogue conversion process occurs on an MPEG chip.

This video filter/driver is also capable of DC coupling on the outputs to improve the low-frequency video, while at the same time eliminating the need for three large capacitors.

Typical designs for set-top boxes offer both S-video and composite-video outputs.

Fairchild's FMS6406 offers separate chrominance and luminance outputs to directly drive the S-video output.

These outputs are also internally summed to form a composite video signal.

The composite- and S-video outputs provide a fixed gain of 6dB and offer the flexibility of either AC or DC coupling.

The FMS6406 is offered in a space-saving 8-pin SOIC package.

This product is lead (Pb)-free and meets or exceeds the requirements of the joint IPC/JEDEC standard J-STD-020B and is compliant with European Union requirements now in effect.

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