Hi, Analog Devices support team.
I am using ADXL326 and evaluate accelalation noise figure now,
The ADXL326 datasheet Rev. 0 | Page 3 of 16 shows that
Noise Density XOUT , YOUT , Z OUT is 300 ug/√Hz rms.
If the Bandwidth was set to 500Hz,the calculated noise rms would be 8.41mG-rms
following the formula shown in the datasheet.
rms Noise = Noise Density × (√BWｘ1.6)
And then, I have measured real noise value.
Xaxis ≒ 4.5, Y axis ≒ 4.6, Z axis ≒ 8.9 (mG-rms).,
Regarding z axis, the calculated value and measured value is similar, but x,y axis is
about half value of the calculated value.
The other hands, the ADXL326 datasheet Page 11 of 16 says that
At V S = 3.6 V, the X- and Y-
axis noise density is typically 120 μg/√Hz, while at VS = 2 V, the
X- and Y-axis noise density is typically 270 μg/√Hz.
I am using this parts with 3.3V, then the noise density should be 130 ug/√Hz rms or so.
( This time, it is similar to x, y measured value.)
Therefore I am confusing which value is correct and how about z axis noise density above?
Could you kindly answer this matter ?
I guess maybe real Z axis noise density spec would be deffrent value from x,y axis spec.
Your reply is highly appreciated.
Best regards,
Yoshiaki
