Products In This Thread

AD7124-8 Recommended for New Designs
The AD7124-8 is a low power, low noise, completely integrated analog front end for high precision measurement applications. The AD7124-8 W grade is AEC...
Datasheet
AD7124-8 on Analog.com

  • State Verified Answer
  • +1 person also asked this people also asked this
  • Replies 1 reply
  • Subscribers 71 subscribers
  • Views 699 views
  • Users 0 members are here
Options
Related 

        

            Post
             Go back to editing
        

    

    


    

    









		












	
	
			
	
			
		
	
	
		

		
How to use AD7124 to measure a series battery module ？



		

			

									
					    Qihui
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Jan 17, 2022 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    Dear，
    

         I use AD7124 to measure a series batteries ， when i connect only one battery ，it works better，
    

    when i connect the three batteries ，the results are wrong .
    

    How to measure many more batteries use AD7124，for example，10-series-battery？
    

     
    
									
			        
		
    

				
				
		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    


	















    
	
    
	
    
					



			








	
	
	
	



Parents
	
      
	

    • 
	
      



	
			
		
	



      
	
      
		
      
							
					
      
		
      
			
													+1
							
			
				
									
							        
			
			
			
      •  Analog Employees  
      •  Super User  
      
            
			                            
                        
                on Jan 18, 2022 1:58 AM
            
            
					
      
	
      

		
		
      
					
      Hi, 
      

      I think what you need to consider here are the accepted input voltage ranges of AD7124 such as Absolute input voltage range (AIN+ or AIN- to GND), Differential Input voltage range (AIN+ - AIN-) and the common mode voltage (AIN+ + AIN-)/2. 

      The datasheet provided all of the restriction regarding these inputs. For example the absolute AIN voltage limits at a gain = 1 (unbuffered) is specified from AVSS - 0.05V to AVDD + 0.05V. If you were to take a look at the above schematic. assuming you have AVDD=3.3V and AVSS=0V, having a 5V input at AIN1 violates this restriction. I'm afraid it may also violated the abs max rating of the part. 
      

      So in general, you need to condition your battery output signal to operate within the ADC input range. 
      

      If you do not want a complex AFE design. I think there is an ADI part that is designed for this type of application. You can check AD7280A (Rev. 0) (analog.com) and then you can ask someone from Q&A - Power By Linear - EngineerZone (analog.com) community to support you on this product, 
      

      Thanks,
      

      Jellenie
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
						
				
				
		
		
      
			
		
      
	
      

      

      • 

	
    



Reply

      


    • 
	
      



	
			
		
	



      
	
      
		
      
							
					
      
		
      
			
													+1
							
			
				
									
							        
			
			
			
      •  Analog Employees  
      •  Super User  
      
            
			                            
                        
                on Jan 18, 2022 1:58 AM
            
            
					
      
	
      

		
		
      
					
      Hi, 
      

      I think what you need to consider here are the accepted input voltage ranges of AD7124 such as Absolute input voltage range (AIN+ or AIN- to GND), Differential Input voltage range (AIN+ - AIN-) and the common mode voltage (AIN+ + AIN-)/2. 

      The datasheet provided all of the restriction regarding these inputs. For example the absolute AIN voltage limits at a gain = 1 (unbuffered) is specified from AVSS - 0.05V to AVDD + 0.05V. If you were to take a look at the above schematic. assuming you have AVDD=3.3V and AVSS=0V, having a 5V input at AIN1 violates this restriction. I'm afraid it may also violated the abs max rating of the part. 
      

      So in general, you need to condition your battery output signal to operate within the ADC input range. 
      

      If you do not want a complex AFE design. I think there is an ADI part that is designed for this type of application. You can check AD7280A (Rev. 0) (analog.com) and then you can ask someone from Q&A - Power By Linear - EngineerZone (analog.com) community to support you on this product, 
      

      Thanks,
      

      Jellenie
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
						
				
				
		
		
      
			
		
      
	
      

      

      • 


    


Children
	
    No Data