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AD7755 Obsolete
The AD7755 is an accurate electrical energy measurement IC intended for use in two-wire distribution systems. It provides instantaneous and average real...
AD7755 on Analog.com

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Problem with the calibration of ad7755

		
	
				

			

									
					    astra91@abv.bg
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Oct 31, 2014 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
		    			
    
			    
    Hello 
    
 
    I am a student and working on a project to measure the DC energy and power ICs AD7755 and I want to ask how to calibrate the integrated circuit I see that different combinations of outputs S0 and S1 and SCF to obtain a different value of the measurement. Is there a difference in the binding of the scheme except that exclude high-pass filter.  What other features does this integrated circuit in DC measurements?
    
			
    
			
									
		                             
                        

    
    
                                            
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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Nov 6, 2014 12:43 AM
            
            
						
			            		
      
		
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      Hi astra91@abv.bg
      
 
      When DC power/energy is to be measured, the calibration procedure isn't affected. Table III shows the max CF output frequency for ac and dc inputs (page 15).
      
 
      However, like you have mentioned, HPF must be disabled by keeping pin 2 at logic 0, for DC inputs. Due to the inherent ADC offsets in the two channels, the power/energy result will have a DC error (page 12 of datasheet). This offset will vary from one IC to another and also over temperature. Figure 14 shows offset distribution over many ICs, at 25C. 
      
 
      Regards
      
 
      hmani
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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                on Aug 2, 2018 10:48 AM
            
            
						
			            		
        
		
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        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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