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AD1939 Production
The AD1939 is a high performance, single-chip codec that provides four analog-to-digital converters (ADCs) with differential input, and eight digital-to...
Datasheet
AD1939 on Analog.com

AD1938 Production
The AD1938 is a high performance, single-chip codec that provides four analog-to-digital converters (ADCs) with input and eight digital-to-analog converters...
Datasheet
AD1938 on Analog.com

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Two AD1939 daisy chained: schematic?

		
	
				

			

									
					    ALodwig607
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Sep 26, 2024 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
    
		      		            		        
    Category: Hardware
    
    		        		            		    
    Product Number:  AD1939  
    
    		        		    		    
    
		    		    
		    			
    
			    
    Dear forum,
    

    we consider driving two AD1939 chips from one BF706 DSP in a daisy-chain setup.
    

    Unfortunately, I did not find any schematic that clearly indicates how to use the SPORT signals.
    

    Is there any resource that I missed?
    

    Also, will there be any impact on analog performance? We will not need more than fs=48kHz.
    

    BR Andre
    

    
			
    
			
									
		                             
                        

    
    
                                            
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      •  Analog Employees  
      •  Super User  
      
            
						
                            
            
            				
            
                on Sep 26, 2024 11:37 AM
            
            
						
			            		
      
		
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      Hello ALodwig607,
      

      

      There is no impact on analog performance and the data in or out is all done during the same sample period. So there is not even a delay between the ADC samples or DAC samples between one chip and the other. 
      

      Table 13 in the datasheet helps to show the direction of the pins. 
      

      There are many more details. Start with figure 18 for the DACs. That diagram explains it. 
      

      You might want to use the Dual Line mode to lower the bit clock rate to make it have a greater timing margin. Figure 19 is for that mode. 
      

      Figure 21 is for the ADC side. 
      

      You probably do not need to run at the faster rate shown in figure 22 unless you have to because of the DAC side. The advantage of running the DAC in dual line is that both the DAC side and ADC side can operate in TDM-8 mode which is better. 
      

      Dave T
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
						
				
				
		
		
      
			
		
      
	
      

      

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