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REF198 for supply AD5612



		

			

									
					    giuseka
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Jul 29, 2011 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    Dear forum,
    
 
    I'm designing a board with one ADC AD7997 and one DAC AD5612. I'm going to use REF198 as a voltage reference for AD7997.
    
 
    Could I use the same REF198 to supply the DAC, that use the supply voltage as the reference?
    
									
			        
		
    

				
						
        

    
    Tags: 
                                            
                 Single-Channel Voltage Output D/A Converters
                
                                                    
                 Multiplexed A/D Converters
                
                                                    
                 ad7997
                
                                                    
                 Series Voltage References
                
                                                    
                 ref198
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                
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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Jul 29, 2011 12:24 PM
            
            
					
      
	
      

		
		
      
					
      Hi-
      
 
      I moved this question to the Precision DACs community.  Please continue the discussion here.
      
 
      Thanks,
      
 
      AndyR
      
 
      EngineerZone Community Manager
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Jul 29, 2011 4:41 PM
            
            
					
      
	
      

		
		
      
					
      Yes you could use the DAC as a reference but you should note the sources of error:
      
 
      
  VOUT-UNI= D/2^12 x (VREF + VGE) +VZSE + INL
 
      
 
      
  where:
 
      
 
      
  VOUT-UNI is unipolar mode worst-case output.
 
      
 
      
  D is code loaded to DAC.
 
      
 
      
  VREF is reference voltage applied to the part. This needs to include the initial accuracy as well as the drift.
 
      
 
      
  VGE is gain error in volts.
 
      
 
      
  VZSE is zero scale error in volts.
 
      
 
      
  INL is integral nonlinearity in volts.
 
      
 
      Noise information is also available in the datasheet. 120nV/root Hz is the NSD at 10kHz and the 1/f noise is 2uV.
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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                on Aug 2, 2018 12:14 PM
            
            
					
        
	
        

		
		
        
					
        This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

        Thank you,
        EZ Admin
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
				
						
						
				
				
		
		
        
			
		
        
	
        

        

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