Products Mentioned

ADA4930-1 Recommended for New Designs
The ADA4930-1/ADA4930-2 are very low noise, low distortion, high speed differential amplifiers. They are an ideal choice for driving 1.8 V high performance...
Datasheet
ADA4930-1 on Analog.com

AD8336 Production
The AD8336 is a low noise, single-ended, linear in dB, general-purpose variable gain amplifier, usable over a large range of supply voltages. It features...
Datasheet
AD8336 on Analog.com

AD9681 Recommended for New Designs
The AD9681 is an octal, 14-bit, 125 MSPS analog-to-digital converter (ADC) with an on-chip sample-and-hold circuit that is designed for low cost, low power...
Datasheet
AD9681 on Analog.com

AD5516 Production
The AD5516 is a 16-channel 12-bit bipolar voltage-output DAC packaged in 74-ball CSPBGA. The part contains a special Increment/Decrement mode which allows...
Datasheet
AD5516 on Analog.com

  • State Verified Answer
  • Replies 4 replies
  • Subscribers 20 subscribers
  • Views 1344 views
  • Users 0 members are here
Options
Related 

        

            Post
             Go back to editing
        

    

    


    

    









		












	
	
			
	
			
		
	
	
		

		
ADA4930-1 Input DC Adjustment from DAC



		

			

									
					    grantd
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Jul 25, 2024 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    Dear Sir/Madam,
    
 
    I am planning on using AD8336, ADA4930-1 and AD9681.
    
 
    AD8336 to ADA4930-1 is DC coupled with unipolar signal that has DC offset.
    
 
    The unipolar signal is connected to the non-inverting input of the ADA4930-1.
    
 
    What options are available to adjust the unipolar signals DC offset so that it is within the 
    
 
    input common mode range of the ADA4930-1 (0V3 to 1V2) ? 
    The adjustment would need to be +- using     AD5516.
    
 

    
 
    Regards Grant
    
									
			                
    Thread Notes   
    
        
    
        
            
		
    

				
						
        

    
    Tags: 
                                            
                 Analog Control Variable Gain Amplifiers (VGAs)
                
                                                    
                 amplifiers
                
                                                    
                 Differential Amplifiers and ADC Drivers
                
                                                    
                 ada4930-1
                
                                                    
                 Voltage Output D/A Converters
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                
                    Show More
            
    
    
    

		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    
















    
	
    
	
    
					



			








	
	
	
	



Parents
	
      
	

    • 
	
      



	
		
	
	



      
	
      
		
      
							
					
      
		
      
			
													0
							
			
				
									
							        
			
			
			
      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Mar 4, 2014 6:18 AM
            
            
					
      
	
      

		
		
      
					
      hi, grantd.
      
 
      I attached the simulation of your circuit using multisim. I also computed the minimum DC offset that the DAC must provide and as long as the DC offset will be above 0.2915V, your signal is within the input range of ADA4930.
      
 
      If you will remove the resistors 50R, 58R4 and 26R7, it will perform as is. The input impedance of ADA4930 without those 3 resistors will be 355ohm. Guide on computing Rin is at page 19 of the datasheet. This is not equal to the 500ohm output load of AD8336 but will still give you desired output.
      
 
      You can try to use the diff-amp calculator, it supports the ADA4930 product and  it allows adjusting your input and see the effect at its output. here's the link where you can download it:
      
 
      http://www.analog.com/en/amplifier-linear-tools/adi-diff-amp-calc/topic.html
      
 
      Regards,
      
 
      Ahbie
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

      • 

	
    



Reply

      


    • 
	
      



	
		
	
	



      
	
      
		
      
							
					
      
		
      
			
													0
							
			
				
									
							        
			
			
			
      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Mar 4, 2014 6:18 AM
            
            
					
      
	
      

		
		
      
					
      hi, grantd.
      
 
      I attached the simulation of your circuit using multisim. I also computed the minimum DC offset that the DAC must provide and as long as the DC offset will be above 0.2915V, your signal is within the input range of ADA4930.
      
 
      If you will remove the resistors 50R, 58R4 and 26R7, it will perform as is. The input impedance of ADA4930 without those 3 resistors will be 355ohm. Guide on computing Rin is at page 19 of the datasheet. This is not equal to the 500ohm output load of AD8336 but will still give you desired output.
      
 
      You can try to use the diff-amp calculator, it supports the ADA4930 product and  it allows adjusting your input and see the effect at its output. here's the link where you can download it:
      
 
      http://www.analog.com/en/amplifier-linear-tools/adi-diff-amp-calc/topic.html
      
 
      Regards,
      
 
      Ahbie
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

      • 


    


Children
	
    No Data