We are using the ADV7340 component to produce Composite standard 640*480 NTSC Square pixel output. We have performed layout according to the datasheet specifications and configured the device to produce this resolution according to the examples at the datasheet. The out put is produced from DAC 1 at full drive output current.

We see that the output video signal is at DC Offset voltage of 90mv from what it should be. The SYNC level is at 90mV instead of 0mV and the blanking is at 90+284=376mv and so on.

Could you please explain this deviation from the Standard and what should I do to fix it.

Best regards

Vladi Dibnis