Products Mentioned

LTM4686 Recommended for New Designs
The LTM4686 is a dual 10A (12A Peak) or single 20A (24A Peak) step-down µModule® (micromodule) DC/DC regulator with 39ms turn-on time. It features remote...
LTM4686 on Analog.com

Thread Details

  • State Verified Answer
  • Replies 2 replies
  • Subscribers 39 subscribers
  • Views 753 views
  • Users 0 members are here 

        

            Post
             Go back to editing
        

    

    


    

    









		


















	
	
			
	
			
		
	
	
		

	    
	    
	    		
Rewriting PSM when using LTM4686 in parallel drive

		
	
				

			

									
					    UBOTI
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Sep 5, 2019 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
		    			
    
			    
    I have the following concerns about using LTM4686, please let me know
    

    

    The LTM4686 is planned to be used in 4-parallel to drive 0.6V to the MCU.
    

     
    

    


    Pin-strapresistors configure start-upsettings(output voltage, register address, phase, etc)
    

    

    Since I want to change the output voltage according to the load, 
    I2C communication is performed from the MCU and the LTM4686 setting is changed 
    so that the register value is read from the resistance value.
    At this time, the address and rail address are also changed.
    

    Since the voltage is applied to the MCU from the LTM4686, there are the following concerns.
    Will the output voltage be reset when the register is rewritten?
    (I am worried that the LTM4686 will not be reset by changing the address)
    
			
    
			
									
		                             
                        

    
    
                                            
                 µModule Regulators
                
                                                    
                 LTM4686
                
                                                    
                 µModule Regulators with Digital Power System Management
                
                                
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                                                    
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

    • 
	
      



	
			
		
	



      
	
      
		
      
							
					
      
		
      
		    
		    		    
			
				
									
							        
			
			
			
      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Sep 6, 2019 6:00 PM
            
            
						
			            		
      
		
										0
					
	
      

		
		
      
		
      
                                
                                                            
      
					
      Hello, 
      

      Resistor configuration externally can set the output voltage and phases at start up.
      

      Once LTM4686 are started, the output voltage can be changed via VOUT_COMMAND register at any time. 
      

      If rail address MFR_RAIL_ADDRESS is required to be changed online, it will not affect the rest of the register values. 
      

      

      Regarding for MFR_ADDRESS, 4 LSB address is decided by the external resistor at ASEL pin and 4 MSB address is decided by the value stored in NVM. For instance, default MFR_ADDRESS is set as 0x4F. When selecting the 1.65K resistor from table 5 from datasheet page 48, the address for this module will be 0x42. As  LSB address is decided by resistor, this LSB value won't be changes via software.
      

      

      Thank you.  
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
				
				
				
		
		
      
			
		
      
	
      

      

      • 

	

    • 
	

      •