Products Mentioned

ADXL203 Recommended for New Designs
The ADXL203 is a high precision, low power, complete dual-axis accelerometer with signal conditioned voltage outputs, all on a single, monolithic IC. The...
Datasheet
ADXL203 on Analog.com

ADXL321 Not Recommended for New Designs
The ADXL321 is a small and thin, low power, complete dual-axis accelerometer with signal conditioned voltage outputs, which is all on a single monolithic...
Datasheet
ADXL321 on Analog.com

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ADXL203 offset with vibration

		
	
				

			

									
					    Roman_
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Jul 16, 2015 
				
			
			
		
    
		
		                    	    
    
        	    
    Thread Summary
    
                The user observed a significant increase in the offset of ADXL203 accelerometers during vibration tests, especially at 150 Hz. The final answer suggests the sensor might be overranging, with the peak events smoothed by the 50 Hz low-pass filter. The user is considering the AD22037 (18g) version to mitigate the issue, as it may have better noise performance. However, another engineer notes that both +5g and +18g versions of the ADXL203 have been used without observing a clear noise advantage for the +18g version. The user also inquires about the replacement for AD22037 and AD22293, as ADXL203 is not recommended for new designs.
                        	    
    
                
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    Hi
    
 
    We are using ADXL203 accelerometers in our device and we have faced the problem: during vibration tests offset of the accelerometers output significaly increases depending of the vibration frequency. 
    
 
    
 
    Biggest offset is at the 150 Hz vibration and reached about 200 mg (see the picture above).
    
 
    ADXL203 bandwithe is set to 50Hz (0.1 uF capacitor).
    
 
    We did not see such effect on the ADXL321 accelerometers placed on the same board with.
    
 
    What is the possible reason of this effect and how can we reduce it.
    
 
    Thanks,
    
 
    Roman. 
    
			
    
			
									
		                             
                        

    
    
                                            
                 sensors
                
                                                    
                 accelerometers
                
                                                    
                 adxl321
                
                                                    
                 adxl203
                
                                                    
                 Sensors and MEMS
                
                                
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                        
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

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      •  Analog Employees  
      •  Super User  
      
            
						
                            
            
            				
            
                on Jul 16, 2015 3:13 PM
            
            
						
			            		
      
		
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      Hi Roman!
      
  
      Thank you for posting this. I suspect that the sensor is being over arranged, but the peak events are being smoothed by your low-pass filter. There is only 0.7g of range on the gravity-aligned axis. Let me think about the ADXL321; I am not as familiar with that device.
      
 
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
				
						
						
				
				
		
		
      
			
		
      
	
      

      

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      •  Analog Employees  
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                on Jul 16, 2015 3:18 PM
            
            
						
			            		
      
		
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      ADXL321 has +/-18g of range. If you tried this on the 18g version of the ADXL203 (AD22037), I suspect that this bias jump will go away.
      
 
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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                on Jul 17, 2015 11:30 AM
            
            
						
			            		
        
		
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        Hi, Mark!
        
 
        Thank you very much for youre answer!
        
 
        I have take a look at AD22037 and AD22293 noise and bias parameters in the datasheet and it looks like 5g devise noise is larger than 18g device noise for the same bandwithe and 18g device noise is very close to 1.7g device. If it is true it looks like we don't need ADXL321 in our project (we use ADXL203/ADXL321 pair because ADXL321 noise performance is too poor for our task). May be I have not take something into account?
        
 
        Regards,
        
 
        Roman.
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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        •  Analog Employees  
        •  Super User  
        
            
						
                            
            
            				
            
                on Jul 17, 2015 2:28 PM
            
            
						
			            		
        
		
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        Hello Roman,
        
 
        We have used both +5g and +18g versions of the ADXL203 in our IMU products and have not observed the advantage in noise for the +18g version, which one would expect based on a review of Table 1 in the ADXL203 datasheet.  In fact, we had seen modest advantages in the +5g version.  So, I would encourage you to try both.  Since they are pin for pin compatible and only vary in their scale factor, comparing them is not as difficult as comparing two completely different devices.  I hope that helps and look forward to future discussions that you start in this forum.
        
 
        Best,
        
 
        NevadaMark
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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                on Nov 4, 2015 10:54 AM
            
            
						
			            		
          
		
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          Hi, Mark
          
 
          Today I found the ADXL203 is not recommended for new designs.
          
 
          Is it applied for all versions (ADXL203, AD22037 and AD22293) or only for 1.7g version?
          
 
          What is a replacement for the AD22037 and AD22293? 
          
			
          

		
			
	      

		
		
	
          
	
          
		
          
			
		
          
	
          
	
          
		
						
						
				
						
				
				
		
		
          
			
		
          
	
          

          

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