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LT3083 Recommended for New Designs
The LT3083 is a 3A low dropout linear regulator that can be paralleled to increase output current or spread heat on surface mounted boards. Architected...
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LT3083 on Analog.com

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Adding Shutdown when LT3083 in parallel

		
	
				

			

									
					    TheOptim
					
							

            
            			
				
									
											
			
			
				
			
			
			    	
			                    
                
				                on Jun 22, 2026 
				
			
			
		

		
		                     
				
        		

		    
		    		    

		      		            		        
Category: Datasheet/Specs

    		        		            		    
Product Number:  LT3083  

    		        		    		    

		    		    
		    			

			    
In LT3083 datasheet, an example was given to add Shutdown when a single LT3083 is in used.    Another example was given showing how to use LT3083 in parallel.


How to add Shutdown when two LT3083 are used in parallel?




  


At the SET pin, it seems follow the example when single LT3083 is used.


However, at OUT, do I need 2 Q2 to connect to OUTs or 1 Q2 to connect to VOUT (after ballast resistors) ?


Thanks in advanced.


Anwar

			

			
									    

			        
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[edited by: TheOptim at 8:00 AM (GMT -4) on 22 Jun 2026]
				

						
		                             
                        

    

                                            
                 Datasheet/Specs
                
                                                    
                 LT3083
                
                                                    
                 LDO Linear Regulators
                
                                
            

    
    
		


				
				        
        		

			
						
									
												
			
			
                        
                                    
                        
                                                    
                        
            
			            
						
						
			
			
			
			
		


        
        
        
    
					

			





















	

	

					



			








	
	
	
	



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                on Jul 8, 2026 7:51 PM
            
            
						
			            		
    
		
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    Hi Harshal,
    

    Thank you for the reply.  From LTspice simulations, using one Q2 transistor after ballast resistors, I can't get true zero Vout when in shutdown, especially for low loads.
    

    In my application, since LT3083 VControl is separate from VIN, I decided to use reed relay to disconnect supply to VControl when shutdown is required.  Using this method, Vout is truly zero in shutdown.
    

    Regards,
    

    Anwar
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
				
				
				
				
		
		
    
			
		
    
	
    

    

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                on Jul 8, 2026 7:51 PM
            
            
						
			            		
    
		
										0
					
	
    

		
		
    
		
    
                                
                                                            
    
					
    Hi Harshal,
    

    Thank you for the reply.  From LTspice simulations, using one Q2 transistor after ballast resistors, I can't get true zero Vout when in shutdown, especially for low loads.
    

    In my application, since LT3083 VControl is separate from VIN, I decided to use reed relay to disconnect supply to VControl when shutdown is required.  Using this method, Vout is truly zero in shutdown.
    

    Regards,
    

    Anwar
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
				
				
				
				
		
		
    
			
		
    
	
    

    

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