Products Mentioned

LT6108 Recommended for New Designs
The LT6108 is a complete high side current sense device that incorporates a precision current sense amplifier, an integrated voltage reference and a comparator...
Datasheet
LT6108 on Analog.com

Thread Details

  • State Not Answered
  • Replies 1 reply
  • Subscribers 0 subscribers
  • Views 329 views
  • Users 0 members are here
Options 

        

            Post
             Go back to editing
        

    

    


    

    









		


















	
	
			
	
			
		
	
	
		

	    
	    
	    		
LT6108 Sense pin

		
	
				

			

									
					    PLeng86
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Oct 18, 2022 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
    
		      		            		        
    Category: Hardware
    
    		        		            		    
    Product Number:   LT6108IDCB-2#TRMPBF 
    
    		        		    		    
    
		    		    
		    			
    
			    
    Hi, I have question on LT6108 in my design.
    

    The minimum supply voltage for LT6108IDCB-2#TRMPBF is 2.7V and usually the SENSEHI is connected to the supply voltage. Is it mandatory to have same voltage on Supply(VCC) and SENSEHI?
    

    My application requires to monitor 2.5V. In this case, Can I apply 3.3V as supply voltage (VCC) and, apply 2.5V to SENSEHI ?
    

     
    

    My circuit is below, help to review it,
    

    

     
    

    thank you.
    
			
    
			
									
		                             
                        

    
    
                                            
                 LT6108IDCB-2#TRMPBF
                
                                                    
                 amplifiers
                
                                                    
                 hardware
                
                                                    
                 lt6108
                
                                                    
                 Specialty Amplifiers
                
                                        
                                            
                
                
                                
                    Show More
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                        
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

    • 
	
      



	
		
	
	



      
	
      
		
      
							
					
      
		
      
		    
		    		    
			
				
									
							        
			
			
			
      •  Analog Employees  
      •  Super User  
      
            
						
                            
            
            				
            
                on Oct 24, 2022 8:28 AM
            
            
						
			            		
      
		
										0
					
	
      

		
		
      
		
      
                                
                                                            
      
					
      

      

      

      Hi PLeng86,
      

       
      

      I agree that in the typical connection, the voltage supply (V+) is connected to the SENSEHI and have the same voltage. However, it is not necessary to have the same voltage since it depends on the application. The amplifier would still work as long as it is within the range.
      

      

      In your case, you want to apply a 3.3V supply voltage and 2.5V in SENSEHI pin. Based on the LT6108 Datasheet, it can function from 0.2V above the positive supply and 33V below it and since 2.5V is within the 33V below the 3.3V supply voltage, you could apply this voltage to your circuit. Also, since the supply voltage is less than 35.5V, the lower range is 2.5 because based on your circuit, V- is connected to the ground.
      

       
      

      Thank you!
      

       
      

      Regards,
      

      Mae
      

      

      

      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

      •