Products In This Thread

AD9954 Production
The AD9954 is a direct digital synthesizer (DDS) that uses advanced technology, coupled with an internal high speed, high performance DAC to form a complete...
Datasheet
AD9954 on Analog.com

AD9102 Production
The AD9102 TxDAC and waveform generator is a high performance digital-to-analog converter (DAC) integrating on-chip pattern memory for complex waveform...
Datasheet
AD9102 on Analog.com

AD9833 Production
The AD9833 is a low power, programmable waveform generator capable of producing sine, triangular, and square wave outputs. Waveform generation is required...
Datasheet
AD9833 on Analog.com

AD9954 Production
The AD9954 is a direct digital synthesizer (DDS) that uses advanced technology, coupled with an internal high speed, high performance DAC to form a complete...
Datasheet
AD9954 on Analog.com

AD9833 Production
The AD9833 is a low power, programmable waveform generator capable of producing sine, triangular, and square wave outputs. Waveform generation is required...
Datasheet
AD9833 on Analog.com

AD9102 Production
The AD9102 TxDAC and waveform generator is a high performance digital-to-analog converter (DAC) integrating on-chip pattern memory for complex waveform...
Datasheet
AD9102 on Analog.com

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DDS with phase marker?



		

			

									
					    jimbles
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Feb 6, 2019 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    Hello,
    

    I am designing a Howland Current Pump, and I have previously used the AD9954 and AD9833 to generate the sine waves. I was looking to use the AD9102 as it seems easier to get hold of from suppliers, and has a broader frequency range for a single clock.
    

    However, one feature I would like to add to my design is a phase marker i.e. a pulse on another pin when zero phase is reached. Is there a DDS IC that has this feature? or is there an example circuit (like a comparator after the DAC output?) 
    

    Thanks for any advice you can offer!
    

    Jimbles
    
									
			        
		
    

				
				
		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    


	















    
	
    
	
    
					



			








	
	
	
	



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      •  Analog Employees  
      
            
			                            
                        
                on Feb 6, 2019 11:54 AM
            
            
												
						in reply to jimbles
					
									
      
	
      

		
		
      
					
      Hello Jimbels,
      

      The datasheet assumes that you either want a sine wave or a square wave, which is the case for most users. But since you want both you can use both. Depends on how much you care about the alignment between the sine wave and the square wave, you might not want to use two separate filters, especially if the two filters have different transfer functions, which looks like the case in the datasheet. You can potentially just have one differential filter between the transformer and IOUT/IOUTB, and feed the comparator from the output of the filter is kick back is acceptable.
      

      Regard,
      

      Will
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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                on Feb 7, 2019 6:10 AM
            
            
												
						in reply to ADIApproved
					
									
        
	
        

		
		
        
					
        Hi Will,
        

        Thanks again for your input. I think an external comparator might be a good solution in my case. I was looking into the AD9102, and there is the DOUT pin which can be controlled by the pattern generator. Does this still work with continuous waveforms? As that might be a good enough for my needs.
        

        Regards,
        

        James
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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        •  Analog Employees  
        
            
			                            
                        
                on Feb 7, 2019 9:05 AM
            
            
												
						in reply to jimbles
					
									
        
	
        

		
		
        
					
        Hello James,
        

        The DOUT pin can be configured to indicate either the pattern generation is on or off. I am not sure if it works in DDS mode, but even if it does, it will just stay high while the DDS is running, rather than send out a rectified (or MSB) of the sine wave.
        

        Regards,
        

        Will
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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													0
							
			
				
									
							        
			
			
			
          
            
			                            
                        
                on Feb 7, 2019 9:31 AM
            
            
												
						in reply to ADIApproved
					
									
          
	
          

		
		
          
					
          Ah I see! That makes sense. Thanks for your continued advice
          

          James
          
			
          

		
			
	      

		
		
	
          
	
          
		
          
			
		
          
	
          
	
          
		
						
						
				
						
				
				
		
		
          
			
		
          
	
          

          

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