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AD9889B Not Recommended for New Designs
The AD9889B is a 165 MHz, high definition multimedia inter-face (HDMI®) v. 1.3 transmitter. It supports HDTV formats up to 1080p, and computer graphic...
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AD9889B on Analog.com

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AD9889B and 1080p60 problem



		

			

									
					    Jacky-zheng
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Jul 1, 2012 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    Hello,
    
 
    I am using an AD9889B,sucessfully transmitting 720p60 and 480p60 signals.
    
 
    Now I tried to transmit 1080p60.
    
 
    AD9889B corrently recognizes the mode that I send to it by reading these registers(R0x3D=0x10,R0x41=0xF8,R0x42=0x10,all circuits powered up and Hot plug active),but the display is black.I've tried many diffrent displays(samsung and others),all displays are black.
    
 
    I modify R0xA2 and R0xA3 to 0X87,and change the timing sequence following EIA-CEA-861-D(verified with a scope),and using videoclock of 148.5MHz,but it's not working.
    
 
    I've tried 1280*768 60Hz too,the videoclock of 108MHz,the display is sign good and black from time to time.
    
 
    I am not using HDCP.
    
 
    Any other regiter must be modfied?
    
 
    many thanks
    
 
    Tom
    
								
    

				
				
		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    


	
    
		
	
    















    
	
    
	
    
					



			








	
	
	
	



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      •  Analog Employees  
      
            
			                            
                        
                on Jul 5, 2012 7:50 PM
            
            
					
      
	
      

		
		
      
					
      Hi Tom,
      
 
      As you have found, I don't think there is anyway the part can work properly in your environment with VCLK so far out of specification, period.
      
 
      Register 0x98 has to do with settings found to work during characterization. Any setting other than 0x7 has not been found to work reliably across temperature / voltage / frequency. 
      
 
      As you lower the clock rate, you get more margin for error and it will work more often despite issues. It's not the basis for a reliable system though.
      
 
      Dave
      
			
      

		
		
		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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      •  Analog Employees  
      
            
			                            
                        
                on Jul 5, 2012 7:50 PM
            
            
					
      
	
      

		
		
      
					
      Hi Tom,
      
 
      As you have found, I don't think there is anyway the part can work properly in your environment with VCLK so far out of specification, period.
      
 
      Register 0x98 has to do with settings found to work during characterization. Any setting other than 0x7 has not been found to work reliably across temperature / voltage / frequency. 
      
 
      As you lower the clock rate, you get more margin for error and it will work more often despite issues. It's not the basis for a reliable system though.
      
 
      Dave
      
			
      

		
		
		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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