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LTM4649 Recommended for New Designs
The LTM4649 is a complete 10A high efficiency switching mode step-down DC/DC μModule® regulator in a 9mm × 15mm × 4.92 BGA package. Included in the...
Datasheet
LTM4649 on Analog.com

LTM4622 Recommended for New Designs
The LTM4622 is a complete dual 2.5A step-down switching mode μModule® (powermodule) regulator in a tiny ultrathin 6.25mm × 6.25mm × 1.82mm LGA and...
Datasheet
LTM4622 on Analog.com

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LTM4649 & LTM4622 Vout start-up and turn-off time

		
	
				

			

									
					    Hiroyuki.D
					
							

            
            			
				
									
											
			
			
				
			
			
			    	
			                    
                
				                on Mar 22, 2018 
				
			
			
		

		
		                     
				
        		

		    
		    		    
		    			

			    
Hi

 
Regarding LTM4649 and LTM4622, I'd like to know Vout start-up time(t1) after reaching RUN pin ON threshold and Vout turn-off time(t2) after falling RUN pin OFF threshold. 

 

 
Regards,

 
Hiroyuki

			

			
									
		                             
                        

    

                                            
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    •  Analog Employees  
    
            
						
                            
            
            				
            
                on Mar 22, 2018 11:50 PM
            
            
						
			            		
    
		
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    Hi Hiroyuki, 
    
 
    Regarding this delay, when the RUN threshold is reached INTVCC gets enabled and once it reaches its UVLO threshold it waits for a number of clock cycles before switching starts. For practical values of soft-start cap you will find that the SS voltage will reach tens of mV (ie 50mV) before you see switching begin and Vout ramp up. You can also look into this in more detail with LTSpice simulations for these parts.  
    
 
    Thanks. 
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
				
				
				
				
		
		
    
			
		
    
	
    

    

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    •  Analog Employees  
    
            
						
                            
            
            				
            
                on Aug 2, 2018 12:03 PM
            
            
						
			            		
    
		
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    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
				
						
				
				
				
		
		
    
			
		
    
	
    

    

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