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LT5400 Recommended for New Designs
The LT5400 is a quad resistor network with excellent matching specifications over the entire temperature range. Matching is also specified when the LT5400...
Datasheet
LT5400 on Analog.com

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LT5400 Resistor Network Matching

		
	
				

			

									
					    BuckiED
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Feb 13, 2023 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
    
		      		            		        
    Category: Hardware
    
    		        		            		    
    Product Number:  LT5400 
    
    		        		    		    
    
		    		    
		    			
    
			    
    Hey all,
    

    I've got a question concerning the matching properties of the LT5400. I want to use the LT5400-3 and need a very precise divider of 6 for one of our ATE units (dividing a up to 60V analog voltage to 10V for a multiplexer). Therefore I connected both 100k resistors in parallel and one of the 10k resistors in series to GND. The datasheet states a matching error of 0.01% (grade A). Does this mean 0.01% between each 100k and 100k / 10k and 10k resistor or is this also meant to be applicable for the ratio between 100k and 10k (10:1)? Because another datasheet parameter is the absolute resistor tolerance which states up to 7.5%. This confuses me a bit and I'm uncertain if this is the correct resistor network for my application of a precise 6:1 divider.
    

    Thanks in advance!
    

    Greetings, BuckiED
    

     
    
			
    
			
									
		                             
                        

    
    
                                            
                 LT5400
                
                                                    
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                 Analog Functions
                
                                                    
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                 Precision Resistor Network
                
                                
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                        
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Feb 13, 2023 1:45 PM
            
            
						
			            		
      
		
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      Hi BuckiED:  The exact values of the resistors part to part can be as much as 7.5% away from the nominal value, but within a specific LT5400-3 the (same value) resistors are matched to each other within 0.01%, and also the ratio.  The exact equation applied in production test is given in Note 6 of the data sheet.
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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                on Feb 14, 2023 1:41 AM
            
            
												
						in reply to ADIApproved
					
										
			            		
        
		
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        Hi Glen,
        

        thanks for your quick answer! So if I understand your reply correctly I don't have to care for the absolute resistor values, because the ratio is still the same every time (in the error margin of 0.01%). Even if the absolute value of R2 and R3 are 10k + 7.5% this means the absolute value of R1 and R4 is 100k with also + 7.5% (+-0.01% in respect to the ratio)? All in all this would always lead to my desired 6:1 voltage divider like I configured above, correct?
        

        Greetings, BuckiED
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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