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AD9699 Recommended for New Designs
The AD9699 is a single, 14-bit, 3 GSPS analog-to-digital converter (ADC). The device has an on-chip buffer and a sample-and-hold circuit designed for low...
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AD9699 on Analog.com

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Reducing sampling speed

		
	
				

			

									
					    OlivierBo
					
							


			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Nov 15, 2024 
				
			
			
		
    
		
		                    	    
    
        	    
    Thread Summary
    
                The user inquires about using the AD9699 ADC at 2 GSPS, despite the minimum rated sampling rate of 2.5 GSPS. The support engineer confirms that while the ADC can function at lower rates, performance will degrade. The SNR degradation at 2 GSPS is expected to be around 1 dB over 700 MHz, which might still be acceptable for the user's application. The AD9689, a dual-channel ADC, is suggested as an alternative but is more expensive.
                        	    
    
                
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    Category: Datasheet/Specs
    
    		        		            		    
    Product Number:  AD9699  
    
    		        		    		    
    
		    		    
		    			
    
			    
    Hi,
    

    We want to use this component to sample at 2 GSPS, and while we understand that most users want the highest sampling rate, 2 GSPS full bandwith sampling fits perfectly our requirement.  Unfortunately in Table 4 "SWITCHING SPECIFICATION" no minimal clock Rate is provided, but the minimal sampling rate is given at 2500MHz. So does this make sense, is really not possible to underclock the converter?
    

     
    

    Later in "clock input consideration" the differential input is qualified between 100MHz and 6 GHz, no minimum is provided
    

     
    

    

    Best regards
    
			
    
			
									
		                             
                        

    
    
                                            
                 Datasheet/Specs
                
                                                    
                 High Speed A/D Converters >10 MSPS
                
                                                    
                 Standard High Speed A/D Converters
                
                                                    
                 AD9699
                
                                
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                        
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Nov 17, 2024 10:32 PM
            
            
						
			            		
      
		
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      Hi  
      

      Thanks for your interest in AD9699.
      

      Unfortunately, this ADC minimum sampling rate is only rated for 2.5 GSPS.
      

      Although, it can still function at lower sampling rate (< 2.5 GSPS) but its performance will be degraded.
      

        
      

      You could also use AD9689 a 14-Bit, 2.0 GSPS/2.6 GSPS, JESD204B, Dual Analog-to-Digital Converter.
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
						
				
				
		
		
      
			
		
      
	
      

      

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                on Nov 20, 2024 3:21 AM
            
            
												
						in reply to JAlipio
					
										
			            		
        
		
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        Hi,
        

        

        Thanks for your answer, unfortunately the AD9689 is a dual channel ADC which cost twice the price of the AD9699. This does not suit our application were cost is an important parameter.
        

        By looking at the curve you provided the SNR degradation seems limited (1dB of degradation over 700 MHz), and may probably still fit our application. Do you have have by any chance a figure about the expected performance degradation if we use it with a sampling frequency of 2000MHZ ?
        

        Best regards
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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