ADXL1002 Accuracy Limitation

Hi engineer team,

 

I was looking on the ADXL1002 datasheet and I was wondering about something : is that significant and accurate to measure a voltage difference which is less than 2mV or 1mV with the ADXL1002 ? We know that the sensitivity is 40mV/g, and the ADXL1002 is made for a huge range +/-50g, so basically the main purpose is not to measure low variation.

I saw as well that the sensitivity due to the temperature is 5% of 40mV/g. So I assume than measuring an acceleration which is lower than 5% of 1g (which means 2mV) is not really accurate.

I am currently asking this cause we are reflecting about which ADC we are gonna use, and I am wondering if a 12bit ADC with a 4V VREF is enough (which allow us to have a resolution of 0.97mV).


Thanks for your help,

Florent

Parents
  • Hi Mark,

    Yes, I got the difference between the resolution and the absolute accuracy !

    All right I understand the example now, there is the same for aiming 10Khz vibration straight after (this is what I am looking for). I am just wondering why in the second example (aiming the 10Khz) the frequency of the low pass filter are 33Khz and 16.5Khz?  The filter is supposed to reduce all the harmonics which got a frequency greater than the Nyquist frequency isn’t it?  

    Ok so this is purely theory formula, I was wondering because I thought it could have been some other parameter.

    Yes, I mean by garbage not reliable data, even if it is based on some real signal. Okep I will have a look on this article.

    Thanks again for your help, much appreciated and useful! 

Reply
  • Hi Mark,

    Yes, I got the difference between the resolution and the absolute accuracy !

    All right I understand the example now, there is the same for aiming 10Khz vibration straight after (this is what I am looking for). I am just wondering why in the second example (aiming the 10Khz) the frequency of the low pass filter are 33Khz and 16.5Khz?  The filter is supposed to reduce all the harmonics which got a frequency greater than the Nyquist frequency isn’t it?  

    Ok so this is purely theory formula, I was wondering because I thought it could have been some other parameter.

    Yes, I mean by garbage not reliable data, even if it is based on some real signal. Okep I will have a look on this article.

    Thanks again for your help, much appreciated and useful! 

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