We do have query for front end voltage divider on analog video input lines for ADV7441 Video decoder as below,
- Refer to ADV7441_HW_RevJ manual, section 3.1, page-22,
o Recommended Resistor Divider Network (24/51 ohm) for 1.6 V Range Video Signal and Recommended Resistor Divider Network (36/39 ohm) for 2 V Range Video Signal
o What should we do if want to support different type of video source in same system (Source-A having 1V range video signal, source-B having 1.6V range video signals and Source-C having 2V video signal)?
We have used 24/51 ohm resistor voltage divider in our circuit (as used in "ADV7441A Typical Connection Diagram"). Below are observation with this,
1. Video source = Sony Camera (720p), video detected but not in sync (see attached waveforms and snap with 01_xx)
2. Video source = DVD player (720p), video detected but not in sync (see attached waveforms with 02_xx)
We replaced votage divider resistors to termination resistors with 0/75 ohm. Below are observation with this,
3. Video source = Sony Camera (720p), video detected (in sync) with BAD colors (see attached waveforms and snap with 03_xx)
As per my understanding typically video signals are of 1V peak to peak, so not able to understand use of voltage divider here.
Thanks & Regards,