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AD8675 Power Up Sequence



		

			

									
						drstein
					
							

			
				
									
											
							 		
		        	            							
			
			    	
			                    
                
				                on Jan 21, 2021 
				
			
			
		


				
		

		    		    
		    
		    	
			
Hi Adi


I use a AD8675 in a circuit just before a DAC. It buffers a voltage reference signal of 5V.


Recently the op amp did not work after a start up. +-15V was applied as supply voltages.




I wonder if start up sequence not was not correct. Maybe 5V on op amp input was applied few uSec before supply voltages were up at AD8675.




How sensitive is the op amp for these situations? Will they typically die? Inserting a resistor to limit current to 10mA is not very convient to or good for the noise performance in actual circuit.




cheers

								


				
				
		

			
						
									
									
						
						
			
			
			
			
		


					

			





	

		
	











	

	

					



			


				
	









	
    
	

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                                 Analog Employees 
                                
                            
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                on Jan 26, 2021 12:54 AM
            
            
					
    
	
    

		
		
    
					
    Hi,
    

    Since there was a possibility of improper power-up sequencing, there is also a chance that your part has been damaged or latch-up has occurred.
    You can do some diode check on your part to check if there are some shorted pins.
    

    If we cannot avoid improper power-up sequencing, it is recommended to have limiting resistor at the input pin of the amplifier.
    

    Thanks and regards.
    
			
    

		
		
		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
				
						
				
				
		
		
    
			
		
    
	
    

    

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