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ADV7611 Recommended for New Designs
The ADV7611 is offered in automotive, professional (no HDCP), and industrial versions. The operating temperature range is −40°C to +85°C. The UG-180...
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ADV7611 on Analog.com

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HDMI to CVBS conversion

		
	
				

			

									
					    Mihalich
					
							


			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Apr 10, 2020 
				
			
			
		
    
		
		                    	    
    
        	    
    Thread Summary
    
                The user inquired about converting HDMI to CVBS using ADV7611 and ADV7393. The final answer confirmed this as a viable solution, recommending the use of 22 or 33 Ohm resistors for HDMI traces and ensuring clean 1.8V power rails with LC filters. The DAC output of the ADV7393 should use a 75 Ohm series resistor and a 75 Ohm load resistor. The user was also advised to cross-check the schematic with the ADV7611 and ADV7393 design support files.
                        	    
    
                
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    Hello.
    

    I found a way to convert HDMI to CVBS with two chips: HDMI->ADV7611->ADV7393->CVBS
    

    Is this the easiest and cheapest solution?
    
			
    
			
									
		                             
                        

    
    
                                            
                 adv7611
                
                                                    
                 HDMI/DVI Receivers
                
                                                    
                 cvbs to hdmi
                
                                                    
                 HDMI/DVI Devices
                
                                
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                        
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			








	
	
	
	



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                on Apr 15, 2020 9:11 AM
            
            
												
						in reply to Mihalich
					
										
			            		
    
		
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    1) Use 22 or 33 Ohm resistors instead of 75 Ohm series resistors.  Normally PCBs are designed for 50 Ohm and you try to match line impedance to the PCB designed impedance.  Need 50 Ohm PCBs for HDMI traces
    

    2) Check out https://ez.analog.com/video/f/q-a/11779/pcb-trace-impedance-calculator for a simple tools to specify PCB trace impedances
    

    3) 1V8_PVDD and 1V8_PVDD_DAC need to be very clean rails.  I don't see the decoupling caps here.  Usually a LC type filter on the rails
    

    4) 7393 DAC output needs a 75 Ohm series resistor with a 75 Ohm load resistor at the end of the cable and the video_out trace designed for 75 Ohm PCB trace.
    

    5) You caught exposed ground pads on both parts.  GOOD.  You don't know how many people miss that.
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
				
						
				
				
		
		
    
			
		
    
	
    

    


	



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							FormerMember
					
      
		
      
			
				
									FormerMember
							        
			
			
			
    
            
						
                            
            
            				
            
                on Apr 15, 2020 9:11 AM
            
            
												
						in reply to Mihalich
					
										
			            		
    
		
										0
					
	
    

		
		
    
		
    
                                
                                                            
    
					
    1) Use 22 or 33 Ohm resistors instead of 75 Ohm series resistors.  Normally PCBs are designed for 50 Ohm and you try to match line impedance to the PCB designed impedance.  Need 50 Ohm PCBs for HDMI traces
    

    2) Check out https://ez.analog.com/video/f/q-a/11779/pcb-trace-impedance-calculator for a simple tools to specify PCB trace impedances
    

    3) 1V8_PVDD and 1V8_PVDD_DAC need to be very clean rails.  I don't see the decoupling caps here.  Usually a LC type filter on the rails
    

    4) 7393 DAC output needs a 75 Ohm series resistor with a 75 Ohm load resistor at the end of the cable and the video_out trace designed for 75 Ohm PCB trace.
    

    5) You caught exposed ground pads on both parts.  GOOD.  You don't know how many people miss that.
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
				
						
				
				
		
		
    
			
		
    
	
    

    





Children
	
            
						
                            
            
            				
            
                on Apr 20, 2020 8:31 AM
            
            
												
						in reply to Mihalich
					
										
			            		
    
		
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    You are correct.  Sorry, I looked at too many schematics that day.