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AD820 Production
The AD820 is a precision, low power FET input op amp that can operate from a single supply of 5 V to 36 V, or dual supplies of ±2.5 V to ±18 V. It has...
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AD820 on Analog.com

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AD820 Junction temperature



		

			

									
					    Terumasa
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Oct 30, 2017 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    Hello
    
 
    Could you  teach me about the junction temperature of AD820 because AD820 datasheet does not describe the junction ?
    
 
    I think that the junction temperature is 150 degree celcius  as other parts and is it correct ?
    
 
    Datasheet describes the internal power dissipation at absolute maximum rate.
    
 
    These are  below and I think that these are defined at 0 degree celcius.
    
 
    But, maximum junction temperature is 160 degree celicus at SOIC.   ( 1.0W  *160 degree celcius/W) .
    
 
    So please let me cralify the junction temeprature of AD820.
    
 
    Internal Power Dissipation at datasheet
    8-Lead PDIP (N) 1.6 W
    8-Lead SOIC_N (R) 1.0 W
    8-Lead MSOP (RM) 0.8 W
    
 
    Regards,
    
 
    Terumasa
    
									
			        
		
    

				
				
		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    


	
    
		
	
    















    
	
    
	
    
					



			


				
	









	
      
	

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      •  Analog Employees  
      
            
			                            
                        
                on Oct 29, 2017 7:32 PM
            
            
					
      
	
      

		
		
      
					
      Hi Terumasa,
      
 
      In computing for the junction temperature of a device you can use the formula: 
      
 
      
 
      Power dissipation is given by the formula:
      
 
      
 
      Assuming quiescent condition and no load is connected, junction temperature of your device at room temp. are:
      
 
      PD @ Vsy = +/-15V, Isy = 900uA
      PD = 27mW
      
 
      TJ(PDIP) = 25C + (90 C/W x 27mW)
      
 
                     = 27.43C
      
 
      TJ(SOIC) = 25C + (160 C/W x 27mW)
      
 
                      = 29.32C
      
 
      TJ(MSOP) = 25C + (190 C/W x 27mW)
      
 
                     = 30.13C
      
 
      If you want to learn more about absolute maximum ratings and thermal resistances you can refer to this Technical Article.
      
 
      Regards,
      Goz
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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      •  Analog Employees  
      
            
			                            
                        
                on Oct 30, 2017 3:30 PM
            
            
					
      
	
      

		
		
      
					
      Hi Terumasa,
      
 
      Junction temperature range is limited to -65C to 150C to avoid violating the absolute maximum ratings. The formulas above can help you in calculating whether you are operating within the range.

      May I know why you needed the information?

      Regards,
      Goz
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
				
						
						
				
				
		
		
      
			
		
      
	
      

      

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                on Oct 30, 2017 11:53 PM
            
            
					
        
	
        

		
		
        
					
        Helloi Gauzz,
        
 
        Thank you for your reply.
        
 
        Could you teach me about the maximum junction temperature of AD820  ?
        
 
        This is not described in the datasheet.
        
 
        Alomost all of parts is desribed as 150 degree celcius but AD820 is not descibed.
        
 
        So ,  our customer asks maximum junction temperature of AD820.
        
 
        Please let me know your advice.
        
 
        Regards,
        
 
        Terumasa
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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													0
							
			
				
									
							        
			
			
			
          
            
			                            
                        
                on Oct 31, 2017 7:04 AM
            
            
					
          
	
          

		
		
          
					
          Hello Goz,
          
 
          Thank you for your answer.
          
 
          Regards,
          
 
          Terumasa
          
			
          

		
			
	      

		
		
	
          
	
          
		
          
			
		
          
	
          
	
          
		
						
						
				
						
				
				
		
		
          
			
		
          
	
          

          

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