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ADV7612 issues with Apple TV

Question asked by JamesL on Dec 9, 2013
Latest reply on Jan 30, 2014 by mattp

We are seeing some strange behaviour with a current (3rd gen) Apple TV feeding into the non-HDCP eval board for the ADV7612 (EVAL-ADV7612EBZ-29) and see the same behaviour with the apple TV feeding our products based on the ADV7611 and ADV7604.


Approximately once per second, the ADV7612 reports loss of TMDS PLL lock and then it reports re-establishing lock. This causes flickering to appear on the screen as the data is not valid during this time. The Eval board is running default power-on settings and the output of the serial port can be seen in the attached log.


We have tried multiple Apple TV units and upgraded the firmware on the devices to the latest revision, but with no effect on this issue. When we feed any of the Apple TVs into a standard TV or one of our older products using an AD9880, the video is fine and we don’t see this unlocking issue. The issue is present at 1080p, 720p and 480p and doesn’t appear to be any worse at higher TMDS frequencies.


We have tried a range of different cables, some short and some long, all with the same effect. This issue is also present when using a recent iPad

or iPhone as the source via a lightning-HDMI adaptor. Older devices (2nd Gen Apple TV and early iPad with larger 30 pin connector) work just fine with our product and the eval board with no flickering and no loss of PLL lock.


Have you seen such issues before with the Apple TV?

Do you have any settings we could try which affect the HDMI PLL?