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ADT7302 Production
The ADT7302 is a complete temperature monitoring system available in SOT-23 and MSOP packages. It contains a bandgap temperature sensor and a 13-bit ADC...
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ADT7302 on Analog.com

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ADT7302 Data Rate and Thermal Time Constant

		
	
				

			

									
					    ricky
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Apr 27, 2015 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
		    			
    
			    
    Hi All,
    
 
    My customer would like to know the maximum available data rate with ADT7302. The data sheet says conversion time is 1.2ms. And the devise clock is reset after every read or write operation for register and this cause the device to start a temperature conversion.
    
 
    Does this mean the maximum data rate through interface is 1/ (1.2ms + register read time), around 80sps. Is this correct?
    
 
    My customer also want to find device which has short thermal time constant. The thermal time constant of ADT7302 is 2 sec. Do you have any other recommendation which has minimum thermal time constant?
    
 
    Best Regards,
    
 
    Ricky
    
			
    
			
									
		                             
                        

    
    
                                            
                 Digital Temperature Sensors
                
                                                    
                 adt7302
                
                                                    
                 Integrated/Special Purpose A/D Converters
                
                                
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                        
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on May 5, 2015 5:20 AM
            
            
						
			            		
      
		
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      Hi Ricky,
      
 
      Your assumption here seems ok. A conversion takes typically 1.2ms, and the internal clock is reset after a write/read operation, so this time is what is conditioning the sample rate as you pointed. Note that a conversion has to be completed before a read occurs, otherwise the result does not get loaded into the temperature value register. Is this sample rate actually critical? Would the 80 SPS you calculated be suitable here? By the way, what frequency is your interface clock running at?
      
 
      The 2 sec thermal time constant data you mentioned is the time the part would take to reach the 63.2% of the final value, but when a thermal shock from 0C to 100C is applied. Would that be your case in your end application? Note also thi 2 sec is a typical value.
      
 
      Regards,
      
 
      Lluis.
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
				
						
						
				
				
		
		
      
			
		
      
	
      

      

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                on May 8, 2015 12:56 PM
            
            
						
			            		
        
		
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        Hi Lluis-san,
        
 
        Thank you for your response.
        
 
        I will talk to my customer based on your advice.
        
 
        Best Regards,
        
 
        Ricky
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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