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ADXL325 Frequency response


what is the mechanical frequency response of the Z-axis of the ADXL325?

In the datasheet the sensor resonance frequency is given as 5.5kHz but then also it is stated that X and Y have a different bandwidth from Z. Can you please elaborate? 


  • Thanks for the question. The sensor resonance frequency describes the mechanical response characteristics of the sensing elements. While the bandwidths incorporate both mechanics and electronics which includes all the filtering from ASIC and external capacitors. Per datasheet states, bandwidths can be selected to suit the application with a range of 0.5 Hz to 1600 Hz for X and Y axes and a range of 0.5 Hz to 550 Hz for the Z axis. 

  • Thank you for the quick reply. 
    So what you are saying is that the mechanical resonance for all thre axes are the same (5.5kHz) but the reason for the Z-axis having a lower bandwidth has to do with internal signal filtering/processing?

    Are there any measurement plots or simulation resulsts showing the mechanical resonances?

  • The 550Hz bandwidth of the Z axis is limited by the suggested o.o1uF external cap to provide a falt response till 550Hz. Since this part has been released for quite a long time, I need to check back if we have documented any simulation results.