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AD9361 Recommended for New Designs
The AD9361 is a high performance, highly integrated radio frequency (RF) Agile Transceiverâ„¢ designed for use in 3G and 4G base station applications....
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AD7291 Production
The AD7291 is a 12-bit, low power, 8-channel, successive approximation analog-to-digital converter (ADC) with an internal temperature sensor. The part...
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DCXO Correction words in FMCOMMS3 - DCXO GUIDE UG570



		

			

									
					    ransara
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Apr 17, 2024 
				
			
			
		
    

				
		
    
		    		    
		    
		    		      		            		        
    Category: Hardware
    
    		        		            		    
    Product Number:  AD9361  
    
    		        		    		    	
			
    Does the FMCOMMS3 come with DCXO correction words pre loaded? If so, what is the frequency they were derived and the nominal temperature?
    

    I assume that when I set the bit D7 of 0x298 and D6 of 0x147 FMCOMMS will correct itself for shifts in crystal due to temperature. Am I correct?
    
										

    
				Added a comma.
    
[edited by: ransara at 10:00 AM (GMT -4) on 17 Apr 2024]
				
    
						
			                
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    Tags: 
                                            
                 fmcomms3
                
                                                    
                 hardware
                
                                                    
                 Multiplexed A/D Converters
                
                                                    
                 dcxo
                
                                                    
                 ad9361
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                
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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Apr 19, 2024 9:52 AM
            
            
					
      
	
      

		
		
      
					
      There are coarse tune and fine tune registers that can be modified using ad9361_set_dcxo_tune function. The resolution of the DCXO varies with coarse word with a worst-case resolution (at coarse word = 0) of 0.0125 ppm. Using both coarse and fine words, the DCXO can vary the frequency over a ±60 ppm range.
      

      The tuning will be a continuous process where you will be increasing or decreasing the word as per the frequency error.
      

      See below plot:
      

       
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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