Hi Sir,

My customer is comparing the noise density between ADXL337 and KXR-90-2050, he found out the ADXL337 noise density is 175ug/Hz and KXR-90-2050 is only 45ug/Hz, it's very big difference in this spec. After I check the competitor's spec, I found out it has 1kHz filter inside to make the noise density become small , so I wonder to know if in same test condition , is ADXL337 better than original spec or do we have any method to make this better througt external component?

KXR-90-2050 data sheet:

You have to look at the output noise.

for the KXR, the bandwidth is 800 Hz, and the noise density is 45. Assuming a first order filter, the output noise would be:

45 * sqrt(1.57*800) = 1.595 mg

for the ADXL337 with the same 800 Hz bandwidth and noise density of 175, the output noise will be:

175 * sqrt(1.57*800) = 6.202 mg

If you didn't need all the bandwidth, you could increase the filtering on the ADXL to lower the noise. Setting the bandwidth to 50 Hz on the ADXL would give it the same noise as the KXR.

175 * sqrt(1.57*50) = 1.550 mg