Products Mentioned

ADP1031 Production
The ADP1031 is a high performance, isolated micropower management unit (PMU) that combines an isolated flyback dc-to-dc regulator, an inverting dc-to-dc...
Datasheet
ADP1031 on Analog.com

ADP1032 Production
The ADP1032 is a high performance, isolated micropower management unit (PMU) that combines an isolated flyback and a dc-to-dc regulator providing two isolated...
Datasheet
ADP1032 on Analog.com

Thread Details

  • State Verified Answer
  • Replies 1 reply
  • Subscribers 34 subscribers
  • Views 1177 views
  • Users 0 members are here
Options 

        

            Post
             Go back to editing
        

    

    


    

    









		


















	
	
			
	
			
		
	
	
		

	    
	    
	    		
Vout3 of ADP1031 not used

		
	
				

			

									
					    baggio
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Dec 19, 2022 
				
			
			
		
    
		
		                    	    
    
        	    
    Thread Summary
    
                The user asked if VOUT3, FB3, and SW3 can be left unconnected if VOUT3 is not used on the ADP1031. The final answer states that SW3 should be floating, VOUT3 should be tied to GND, and FB3 must be within 0.8V to 0.88V relative to VOUT3/GND to disable SW3 and retain PWRGD functionality. A resistor divider from VOUT2 can be used to set the FB3 voltage, e.g., 10kΩ and 51.5kΩ for a 5V VOUT2.
                        	    
    
                
                     AI Generated Content
                
    	    
    
             
				
        		
    
		    
		    		    
    
		      		            		        
    Category: Hardware
    
    		        		            		    
    Product Number:  ADP1031 
    
    		        		    		    
    
		    		    
		    			
    
			    
    Hello.
    

    I have a question. Please tell me.
    

    If VOUT3 is not used, can VOUT3, FB3 and SW3 be left unconnected?
    

    I think the ADP1032 is recommended, but I am considering whether it can be replaced because there are no parts.
    

    Best Regards.
    
			
    
			
									
		                             
                        

    
    
                                            
                 adp1032
                
                                                    
                 hardware
                
                                                    
                 isopower
                
                                                    
                 Digital Isolation Technology
                
                                                    
                 adp1031
                
                                
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                        
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

    • 
	
      



	
			
		
	



      
	
      
		
      
							
					
      
		
      
		    
		    		    
			
				
									
							        
			
			
			
      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Dec 27, 2022 9:45 PM
            
            
						
			            		
      
		
										+1
					
	
      

		
		
      
		
      
                                
                                                            
      
					
      Hi baggio,
      

      

      The inverter/VOUT3 on the ADP1031 can be disable by:
      

        

      1. removing the inductor connected to SW3, SW3 should be floating.
        2. 

      2. VOUT3 should be tied to GND.
        3. 

      3. FB3 must be supplied within this range 0.8V < VFB3 < 0.8V +10% in reference to VOUT3/GND to disable the SW3 from turning on.

          

        1. The voltage on FB3 can be generated from VOUT2 through resistor dividers. For example, for 5V VOUT2 – use 10kohm across the FB3 and VOUT3/GND. Use 51.5kohm resistor across VOUT2 and FB3. This resistor divider combination will give 0.818V on FB3 in reference to VOUT3/GND.
          2. 

        

        4. 

      

      This will not only disable the switching of the SW3 but also retain the PWRGD functionality.
      

      Thanks,
      

      Jefferson
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
				
						
						
				
				
		
		
      
			
		
      
	
      

      

      •