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ADP2118 Production
The ADP2118 is a low quiescent current, synchronous, step-down dc-to-dc regulator in a compact 4mm × 4mm LFCSP package. It uses a current mode, constant...
Datasheet
ADP2118 on Analog.com

ADP2164 Recommended for New Designs
The ADP2164 is a 4 A, synchronous, step-down dc-to-dc regulator in a compact 4 mm × 4 mm LFCSP package. The regulator uses a current mode, constant frequency...
Datasheet
ADP2164 on Analog.com

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Minimum Inductor Value of ADP2118



		

			

									
					    Tarzan
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Aug 27, 2013 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    Hi everyone.
    
 
    I have a question about ADP2118.
    I'm useing ADP2118 in  the following condiiton; Vin-5V, Vout-3.3V(Duty: about 0.7).
    But how should I caluculate Minimum vallue of INDUCTOR?
    I can't find any caluculating fomula on the datasheet.
    
 
    I also consder ADP2164, but I can't find the infromatoin on minimum value of Inductor.
    Please tell me if the calucuating fomula is the same as ADP2118.
    
 
    The datasheet just say something like that;
    The ADP2118 uses slope compensation in the current loop to prevent subharmonic oscillations when the duty cycle is larger than 50%.
     The internal slope compensation limits the minimum inductor value.
    
 
    Best regards,
    Tarzan
    
									
			        
		
    

				
						
        

    
    Tags: 
                                            
                 adp2118
                
                                                    
                 Internal Power Switch Buck Regulators
                
                                                    
                 adp2164
                
                                                    
                 Step-Down (Buck) Regulators
                
                                
            
    
    
    

		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    
















    
	
    
	
    
					



			








	
	
	
	



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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Aug 27, 2013 6:34 PM
            
            
					
      
	
      

		
		
      
					
      Tarzan,
      
 
      the min inductor value for the ADP2118 is around 1.5uH. It is not described in the datasheet because different inductors (even if specified at 1.5uH) may have lower inductance at full load.
      
 
      The best way to determin the min inductance for the internally compensated parts is to actually use the design tools and select from list of available inductor values. That list not only considers the min and max inductor values but also considers the inductance value of the part under the operating conditions.
      
 
      ADP21xx Buck Regulator Design Tool 
      
 
      supports: ADP2105, ADP2106, ADP2107, ADP2108, ADP2109, ADP2118, ADP2119, ADP2120, ADP2138, ADP2139, ADP2164
      
 
      Best Regards,
      
 
      LucaV
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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													0
							
			
				
									
							        
			
			
			
      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Aug 27, 2013 6:34 PM
            
            
					
      
	
      

		
		
      
					
      Tarzan,
      
 
      the min inductor value for the ADP2118 is around 1.5uH. It is not described in the datasheet because different inductors (even if specified at 1.5uH) may have lower inductance at full load.
      
 
      The best way to determin the min inductance for the internally compensated parts is to actually use the design tools and select from list of available inductor values. That list not only considers the min and max inductor values but also considers the inductance value of the part under the operating conditions.
      
 
      ADP21xx Buck Regulator Design Tool 
      
 
      supports: ADP2105, ADP2106, ADP2107, ADP2108, ADP2109, ADP2118, ADP2119, ADP2120, ADP2138, ADP2139, ADP2164
      
 
      Best Regards,
      
 
      LucaV
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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