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LT8390 Recommended for New Designs
The LT8390 is a synchronous 4-switch buck-boost DC/DC controller that regulates output voltage, input or output current from an input voltage above, below...
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LT8390 on Analog.com

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Question about LT8390

		
	
				

			

									
					    Kazu
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Dec 14, 2022 
				
			
			
		
    
		
		                    	    
    
        	    
    Thread Summary
    
                The user inquired about using a single LT8390 for a 600W buck/boost output with 18V to 28V input and 24V, 25A output. The support engineer confirmed it is possible but would require bulky components and multiple MOSFETs, with a high inductor current (>30A saturation). LTpowerCAD was suggested for design assistance, and the user noted that simulations with recommended circuits only worked up to 300W output.
                        	    
    
                
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    Category: Datasheet/Specs
    
    		        		            		    
    Product Number:  LT8390 
    
    		        		    		    
    
		    		    
		    			
    
			    
    Hi,
    

    I am considering to use LT8390 with the following specs.
    

    Vin=18V to 28V
    

    Vout=24V, Iout=25A max  (Pout=600W max)
    

    

    Is it possible to use a single LT8390 for 600W buck/boost output? 　
    

    If so, what precautions should be taken in circuit design?
    

    If not, are there any products that can meet the above specs?
    

    Regards,
    

    Kazu
    
			
    
			
									
		                             
                        

    
    
                                            
                 Datasheet/Specs
                
                                                    
                 lt8390
                
                                                    
                 External Power Switch Buck-Boost Controllers
                
                                                    
                 Buck-Boost Regulators
                
                                
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                                                    
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			








	
	
	
	



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							FormerMember
					
      
		
      
		    
		    		    
			
				
									FormerMember
							        
			
			
			
    
            
						
                            
            
            				
            
                on Dec 14, 2022 2:45 AM
            
            
						
			            		
    
		
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    Hello Kazu,
    

    

    You can use LTpowerCAD to help you with your design requirement.
    

    These are some of the controllers that were suggested by LTpowerCAD when inputting your specs.
    

    

     
    

    

    Regards,
    

    Jhun
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
				
				
				
				
		
		
    
			
		
    
	
    

    


	

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                on Dec 14, 2022 3:42 AM
            
            
												
						in reply to FormerMember
					
										
			            		
      
		
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      Hi Jhun,
      

      I get the same products as yours for sure in LTpowerCAD except for LTC4020.
      

      I exported some recommended circuits showed in Power Stage Design to LTspice and simulated them, but they did not output 600W (24V/25A),
      

      They could work when the output current reduced to about 300W.
      

      Is it still difficult to achieve 600W output?
      

      Regards,
      

      Kazu
      

      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
				
				
				
		
		
      
			
		
      
	
      

      

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							FormerMember
					
      
		
      
		    
		    		    
			
				
									FormerMember
							        
			
			
			
            
						
                            
            
            				
            
                on Dec 14, 2022 7:00 PM
            
            
												
						in reply to Kazu
					
										
			            		
      
		
										+1
					
	
      

		
		
      
		
      
                                
                                                            
      
					
      Hi Kazu,
      

      600W is achievable but you would have bulky components. Plus, you would need >2 MOSFETs in your control and sync MOSFETs since it is a single phase.
      

      The datasheet has computation guidelines on how to compute for your desired specifications. I would think you'd need a high inductor current >30A saturation. I have ever only seen Wurth inductors having these.
      

      

      Regards,
      

      Jhun 
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
				
				
				
		
		
      
			
		
      
	
      

      

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							FormerMember
					
        
		
        
		    
		    		    
			
				
									FormerMember
							        
			
			
			
      
            
						
                            
            
            				
            
                on Dec 14, 2022 7:00 PM
            
            
												
						in reply to Kazu
					
										
			            		
      
		
										+1
					
	
      

		
		
      
		
      
                                
                                                            
      
					
      Hi Kazu,
      

      600W is achievable but you would have bulky components. Plus, you would need >2 MOSFETs in your control and sync MOSFETs since it is a single phase.
      

      The datasheet has computation guidelines on how to compute for your desired specifications. I would think you'd need a high inductor current >30A saturation. I have ever only seen Wurth inductors having these.
      

      

      Regards,
      

      Jhun 
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
				
				
				
		
		
      
			
		
      
	
      

      





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