CVBS to HDMI conversion

Thanks GuenterL.

   You are right, for CVBS alone it is an overkill. We are trying to utilize the other features also.

May I know the part status? Is it recommended for new designs?

We are trying to use the VGA conversion also with 3 more additional HDMI mux

So total inputs will be 1x VGA + 1x CVBS + 3x HDMI

Does this require DDR Chip in the above application?  

Both ADV7850 and ADV7842 are recommended for new designs.  Check out https://ez.analog.com/video/w/documents/721/read-first-design-support-files-overview

Only the ADV7850 can handle 3 HDMI inputs.

The ADV7850 requires DDR while the ADV7842 does not require DDR if you drop 3D comb and TBC features.

I'd suggest purchasing a EVAL-ADV7850EBZ board for evaluation.

Note you will have to be an HDCP and HDMI adopter to purchase the 7850 eval board.

Thanks Guenter,

      As per the datasheet , there is 4:1 HDMI mux,  confused with your statement 3 . Is it a limitation ?. Following is our application plan. Can you check the below and comments?

We have the HDMI adopter license. We already used this chip in another project for VGA to HDMI with another HDMI input through the mux. In this we haven't used the DDR interface. 

Hi

   Can you update on the DDR requirement 

Following is our current requirement, HDMI mux moved to external for supporting 4K 60Hz

Now we use 3 inputs ( CVBS, YPbPr and VGA). and 1x HDMI out

We already use this chip in our another design which used to convert VGA with extra HDMI input mux, we haven't used the DDR.

Does DDR required for the new requirement ?

Hi,

 The external DDR2 memory is required only for 3D comb and Frame TBC operation.
It support Advanced time-base correction (TBC) with frame synchronization for SD formats.

 The ADV7850 supports a DDR2 memory interface. Depending on the feature required, the appropriate memory device can be selected. It can use DDR2 external memory to simultane-ously provide 3D comb and frame TBC operation.

Thanks,

Poornima

The ADV7850 requires DDR if the SDP module is used and in this application CVBS is present so DDR is required.  If if was a ADV7844/7511 solution then external DDR can be dropped if 3D Comb and TCB features are dropped.  Note ADV7844 has 4 HDMI inputs where the ADV7842 has only 2.

The ADV7850 should be able to handle 4k30.  See private, off-line email. 

The best bet is to get a ADV7850 reference board and try all the different formats you are interested in.  I personally have not tried 4K30 on the ADV7850 but the spec's say it should work.