Products Mentioned

LTC4368 Recommended for New Designs
The LTC4368 protects applications from power supply voltages that may be too high, too low, or even negative and from overcurrent faults in both forward...
Datasheet
LTC4368 on Analog.com

  • State Not Answered
  • Replies 1 reply
  • Subscribers 39 subscribers
  • Views 191 views
  • Users 0 members are here
Options
Related 

        

            Post
             Go back to editing
        

    

    


    

    









		












	
	
			
	
			
		
	
	
		

		
LTC4368-2 Not powering up/not enabling gate voltage to allow voltage to pass through



		

			

									
					    Poley
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Dec 1, 2023 
				
			
			
		
    

				
		
    
		    		    
		    
		    		      		            		        
    Category: Hardware
    
    		        		            		    
    Product Number:  LTC4368HDD-2#WPBF 
    
    		        		    		    	
			
    Hi all, I have a new board made which contacins the LTC4368-2. I am having an issue where no matter what voltage I put on VSUP I get no gate drive and therefore no voltage passing through to VIN. I have checked my resistor values to the equations in the datasheet and it appears to be right? I am wondering if I am missing something obvious? Thanks!
    

    

    

     
    
									
			        
		
    

				
						
        

    
    Tags: 
                                            
                 hardware
                
                                                    
                 Power Monitor  Control  and Protection
                
                                                    
                 LTC4368HDD-2#WPBF
                
                                                    
                 ltc4368
                
                                                    
                 Surge Stopper  Overvoltage  and Overcurrent Protection
                
                                
            
    
    
    

		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

    • 
	
      



	
		
	
	



      
	
      
		
      
							
					
      
		
      
			
													0
							
			
				
									
							        
			
			
			
      •  Analog Employees  
      •  Super User  
      
            
			                            
                                                                                                                        
            
				
			
            
					
      
	
      

		
		
      
					
      At a glance, schematic looks ok.
      Build in LTSpice to convince yourself it works.

      Quick troubleshooting:
      

        

      1. Remove regular load from output and replace with a 100ohm to 1k power resistor.
        2. 

      2. Add a 10k pullup from FAULT# to VSUP so you can check fault status.
        3. 

      3. Remove R15 to disable UV-OV window.
        4. 

      4. Apply 12V to VSUP.
        5. 

      5. What is Vout? What is Vgate? What is Vfault#?
        6. 

      6. Probe C22 (RETRY pin) - is there a triangle waveform?
        7. 

      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

      •