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Understanding the compatibility between Amplifier and Encoder

Question asked by jayeshtanwani on May 28, 2016
Latest reply on Jul 1, 2016 by GuenterL


Our requirement is that an Y/C NTSC video signal be converted to a PAL video.

We selected two amplifiers, a decoder and an encoder. We would like to know if the parts selected have proper compatibility and also serve our purpose.

On the input side we have selected ADA4830-2 as the amplifier. The input signal is 2V p-p pseudo differential unbalanced S-Video.

As per datasheet "closed-loop differential to single-ended gain of the video channel is internally fixed at 0.50 V/V (-6 dB) to ensure compatibility with video decoders whose input range is constrained to 1 V p-p or less".

The decoder which accepts this output is ADV7182 and accepts S-Video and converts to YCrCb. Also the amplifier converts pseudo differential input to single-ended which can be accepted by the decoder.


On the output side we are using ADV7391 as the video encoder for conversion of the YCrCb to S-Video, the output from this is a 1V p-p single-ended signal.

This is given to amplifier ADA4432-1, which having a gain of 2 can produce a 2V p-p pseudo differential unbalanced signal.


Attached the pictorial representation of the above said.


Please let us know if our understanding is correct and the parts selected are compatible.


Thank you,

Jayesh Tanwani