Products Mentioned

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

Associated Drivers

  • State Verified Answer
  • Replies 10 replies
  • Answers 1 answer
  • Subscribers 25 subscribers
  • Views 2514 views
  • Users 0 members are here
Options
Related 

        

            Post
             Go back to editing
        

    

    


    

    









		












	
	
			
	
			
		
	
	
		

		
AD9102 - Trouble with DDS mode and reading from SRAM??



		

			

									
					    daniel1.hong@intel.com
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Jul 22, 2015 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    I have the AD9102 EVboard and I can get all modes to work: constant value, Sawtooth, DDS, and reading from SRAM.  However, on my proto-layout board, I program the Ad9102 SPI directly and I can only get the constant value and Sawtooth mode to work.  The DDS and read from SRAM do not give any output.  I am taking the regval and default sequence from the EVboard software and and programming into AD9102 SPI directly.  So inputting example4 settings gives me the pulsed triangle wave for the sawtooth mode which is working, but the sine wave of example6 is not working.  The registers and SRAM are able to read and write properly. Is this a common problem or am I missing something obvious?  Any help would be appreciated, thanks.
    
									
			        
		
    

				
						
        

    
    Tags: 
                                            
                 ad9102
                
                                                    
                 clock and timing
                
                                                    
                 Direct Digital Synthesis (DDS)
                
                                
            
    
    
    

		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    
















    
	
    
	
    
					



			








	
	
	
	



Parents
	
      
	

    • 
	
      



	
		
	
	



      
	
      
		
      
							
					
      
		
      
			
													0
							
			
				
									
							        
			
			
			
        
            
						
                            
            
            				
            
                on Aug 6, 2015 4:57 AM
            
            
					
        
	
        

		
		
        
					
        Hi Biao,
        
 
        I didn't get to create the example1 patterns, but I did have example2 patterns already.  I believe ex2 does use only the SRAM addresses out to DAC.  I do see that the WAV_CONFIG reg reads back as 0x0001 instead of 0x3030.  If i try to program WAV_CONFIG alone, it will read back correctly, but i don't understand why it would get pushed out when i program a string of the registers together. Note that example4 fires up no problem on my protoboard, just not the SRAM modes.
        
 
        So I put a 3.3V regulator for each of the power supply pins, using ferrite bead inductor to 2 caps, and I also put 100pF and 0.1uF up close to the AD9102 pin.  All grounds are to ground plane.  
        
 
        -What would be the result of noise feeding to the supplies? could that cause registers to lose value?
        
 
        -I read that writing the RAMUPDATE bit pushes the buffered register settings to the active register settings.  How many times can you do a RAMUPDATE before active register goes to 0x0 or default value?  
        
 
        -Does RAMUPDATE clear any registers that were not written into the buffer registers? 
        
 
        -Do you know of any specific sequence order of registers that need to be programmed?  I note the reg sequence for the DAC1 tab programming from EVboard below.
        
 
        Thanks again for the help.
        
 
        Dan
        
 
        DAC1 tab write:
        
 
        0x45
        
 
        0x5D
        
 
        0x5E
        
 
        0x5C
        
 
        0x27
        
 
        0x1F
        
 
        0x2B
        
 
        0x35
        
 
        0x25
        
 
        0x3E
        
 
        0x3F
        
 
        0x43
        
 
        0x31
        
 
        0x37
        
 
        0x47
        
 
        0x5F
        
 
        0x1D
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

        • 

	
      



Reply

        


      • 
	
        



	
		
	
	



        
	
        
		
        
							
					
        
		
        
			
													0
							
			
				
									
							        
			
			
			
          
            
						
                            
            
            				
            
                on Aug 6, 2015 4:57 AM
            
            
					
          
	
          

		
		
          
					
          Hi Biao,
          
 
          I didn't get to create the example1 patterns, but I did have example2 patterns already.  I believe ex2 does use only the SRAM addresses out to DAC.  I do see that the WAV_CONFIG reg reads back as 0x0001 instead of 0x3030.  If i try to program WAV_CONFIG alone, it will read back correctly, but i don't understand why it would get pushed out when i program a string of the registers together. Note that example4 fires up no problem on my protoboard, just not the SRAM modes.
          
 
          So I put a 3.3V regulator for each of the power supply pins, using ferrite bead inductor to 2 caps, and I also put 100pF and 0.1uF up close to the AD9102 pin.  All grounds are to ground plane.  
          
 
          -What would be the result of noise feeding to the supplies? could that cause registers to lose value?
          
 
          -I read that writing the RAMUPDATE bit pushes the buffered register settings to the active register settings.  How many times can you do a RAMUPDATE before active register goes to 0x0 or default value?  
          
 
          -Does RAMUPDATE clear any registers that were not written into the buffer registers? 
          
 
          -Do you know of any specific sequence order of registers that need to be programmed?  I note the reg sequence for the DAC1 tab programming from EVboard below.
          
 
          Thanks again for the help.
          
 
          Dan
          
 
          DAC1 tab write:
          
 
          0x45
          
 
          0x5D
          
 
          0x5E
          
 
          0x5C
          
 
          0x27
          
 
          0x1F
          
 
          0x2B
          
 
          0x35
          
 
          0x25
          
 
          0x3E
          
 
          0x3F
          
 
          0x43
          
 
          0x31
          
 
          0x37
          
 
          0x47
          
 
          0x5F
          
 
          0x1D
          
			
          

		
			
	      

		
		
	
          
	
          
		
          
			
		
          
	
          
	
          
		
						
						
				
						
				
				
		
		
          
			
		
          
	
          

          

          • 


        


Children
	
        No Data