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ADG772 USB 2.0 480Mbps Eye diagram



		

			

									
						JerryS
					
							

			
				
									
											
							 		
		        	            							
			
			    	
			                    
                
				                on May 6, 2015 
				
			
			
		


				
		

		    		    
		    
		    	
			
Hello,

 
I design in ADG772BCPZ for portable USB storage application with SATA controller ASM1153E

 
customer takes his own product to do USB 2.0 480Mbps test in certification lab, but the eye diagram is fail.

 
After fail, customer provide ADG772 EVB to lab re-test. ADI EVB is test fail, too. 

 
customer provide ADG772 EVB condition, and eye diagram as below.

 
please kindly give me some of suggestion.

 

 

 

								


				
				
		

			
						
									
									
						
						
			
			
			
			
		


					

			





	

		
	











	

	

					



			


				
	









	
    
	

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                                 Analog Employees 
                                
                            
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                on May 8, 2015 2:46 PM
            
            
					
    
	
    

		
		
    
					
    Hi Jerry,
    
 
    There seems to be a lot of jitter and noise on the signal. Also the fact that the device failed the eye diagram in your design and the evaluation board would suggest that maybe the noise is a result of the USB controller or the connection from the controller to the ADG772 rather than the device itself. For example, the length and the quality of the cables used to connect the signal to the ADG772 evaluation board would have an effect on the signal quality, rise/fall times, etc. So maybe investigating the integrity of the signal being presented to the ADG772 may offer a solution.
    
 
    Regards,
    
 
    Stephen
    
			
    

		
		
		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
				
						
						
				
				
		
		
    
			
		
    
	
    

    

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