I'm working with the IIS3DWB high-performance MEMS accelerometer and using it to calculate both acceleration RMS and velocity RMS values.
While the datasheet specifies a frequency response from DC to 6 kHz (±3 dB), I’ve noticed in practice that reliable and accurate RMS measurements only begin to appear from around 40 Hz onwards.
After enabling the digital high-pass filter (HPF) as shown in the documentation (see attached figure), I understand that the minimum cutoff is ODR/800, which translates to 33 Hz at an ODR of 26667 Hz. This explains the attenuation of low-frequency components and might be contributing to the inaccuracy in the 2–40 Hz band.
What is the best way to achieve accurate acceleration and velocity RMS values in the 2 Hz to 40 Hz frequency range using the IIS3DWB?
Any suggestions or community experience on low-frequency analysis with this sensor?
