We are currently using an ADV7181D to decode VGA (1024 x 768 @60Hz) to 16 bit YUV 422. After looking at the scripts for the ADV7181D (:RGB 1024x768 _@ 60Hz 12-Bit DDR 65.000MHz Out through HDMI:) and the scripts for the ADV7401 (:TT 1024x768 @_60Hz, 16 Bit 422 YCrCb SD Space Out from Decoder, RGB o/p from Encoder Through HDTV RGB Port ADI CSC:), as mentioned in another post.
We have manged to get 16 bit YUV422 data out. However we have noticed that the ADV7181D is getting hot - is this normal? or are there a few register settings that we have missed that would optimize the power consumption. Checking with a thermal camera the device is getting to around 70 deg C. I have also checked and double checked our design against the reference board and everything looks correct.
Any help on this subject would be appreciated.
Make sure you have powered down the unused ADC, VGA only needs 3 up and running.
What is is around the chip that could be effecting heat dissipation?
Are you seeing this at other resolutions as well? XGA is the top end of the supported formats for the part so it's not all that suprising that it would get warm.
What sort of current draw are you seeing on DVDD and AVDD? I would expect to see roughly 800-900mW being used in your situation.
Thanks for the quick reply. ADC is turned off, and the device is soldered to a large centre ground pad which is connected to the main ground plane with a number of vias. As I have mentioned, I have used an amalgamation of the ADV7181D script and the ADV7401 script. I am currently seeing a round 1.4W which seems a bit high. I have seen it mentioned in the manual that the register settings need to be correct for correct thermal performance. I have attached the register settings I have used.
Checking with ADV7181D expert for power numbers.
The highest typical power occurs with SCART input when all 4 ADCs are running. should be about 0.95W. 1.4W seems a bit high when talking to the experts also.