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use a ADM706T with a Microchip PIC?



		

			

									
					    ekoester
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Aug 23, 2012 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    I've got a project with the SHARC 21489 and it also has an 18F serise PIC.  I'm planning to use an ADM706T as a voltage monitor reset and a watchdog reset for the SHARC.  It would be nice to use the ADM706T to reset both the SHARC and the PIC.
    
 
    The only issue I see is that the MCLR line on the PIC (used for reset) is also used as a programming pin and is pulled to 12V during programming of the PIC.  I'm concerned that the 12V will damage the ADM706T and the RESET pin on the SHARC.
    
 
    Is it safe to include the PIC's MCLR line on the RESET output of the ADM706T?
    
 
    Eric
    
									
			        
		
    

				
						
        

		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    


	
    
		
	
    















    
	
    
	
    
					



			


				
	









	
      
	

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      •  Analog Employees  
      
            
			                            
                                                                                                                        
            
				
			
            
					
      
	
      

		
		
      
					
      Hi Eric,
      
 
      Neither SHARC21489 nor ADM706 (nor most of the reset ICs) would be able to withstand 12V on their pins.
      
 
      The requirement of 18F series PIC is quite unique, and after some research, you can either do it with discrete components as shown below:
      
 
       
      
 
      Or you may choose to use a reset generator from the same company that does the PICs that is specially designed to work with PICs that require ICSP.
      
 
      Ren
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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        I may end up using a PIC GPIO pin to reset the SHARC.
        
 
        I'm also thinking of using a zener diode and isolation resistor to protect the ADM706T and the SHARC RESET pin from the 12V PIC programming voltage.
        
 
        Eric
        
 
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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        •  Analog Employees  
        
            
			                            
                                                                                                                        
            
				
			
            
					
        
	
        

		
		
        
					
        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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