Thomas Schmidt

the problem

AppleTV is rightly designed for HDTV ready Televisions and provides only a HDMI and a YPrPB interface for TV. Surely for some people, and for me, there is a need to converting it to a conventional TV compatible signal.

Please Note - You can order this as preassembled kit. SMD is already soldered. >>>>Embedded Projects Shop<<<<

the solution


yprpb2rgb/schematic.jpg The circuit is based on the LMH1251 chip from National Semiconductors. Composite SYNC is extracted from the Y-Signal yprpb2rgb/board-1.jpg yprpb2rgb/board-2.jpg with the LM1881 - also from National Semiconductors, although the LMH1251 has V/H-SYNC Output separated. yprpb2rgb/board-3.jpg Tests to use this outpus where not successfull and cause i had good experiences with the Sync-Seperator LM1881, it was used. On the prototype board you can see the different SYNC test circuits ( a test with a logic gate at the middle top - a test with a single transistor at the bottom right and the LM1881 at the middle bottom )

On the pictures you can see also the stabilized 5V power supply, the ensamble with the AppleTV and the traditional color TV.


I buld a 2nd prototype on a selfmade PCB. The final Layout is downloadable now ! yprpb2rgb/PCB-all3.jpg High resolution version
Schematic, PCB Layout (PDF)YPrPb2RGB-v2.3.pdf

Feel free to ask for EAGLE CAD files !

The CAD software is provided by - a free limited version should be available there.

Complete PCB

yprpb2rgb/board-4.jpg yprpb2rgb/board-5.jpg yprpb2rgb/board-6.jpg yprpb2rgb/board-7.jpg yprpb2rgb/board-8.jpg