What type of filter is it?

[VSavenia]

In application note said that "The accelerometer sampling chain is represented by a cascade of three main blocks: an ADC converter, a digital low-pass filter (LPF1) and the composite group of digital filters". I want to know what type of filter is LPF1. Is it IIR or FIR filter.

Regards.

[Eleon BORLINI · Accepted solution]

Hi @VSavenia​ ,

the LPF1 should be a FIR filter that is equivalent to an analog filter with cutoff frequency at ODR/2.

You can moreover increase the low pass filter "attenuation strength" acting on LPF2 further downstream of the circuit.

-Eleon

[VSavenia]

Ok, and what about LPF2 filter, what type is it?

[Eleon BORLINI]

Hi @VSavenia​ ,

it is a similar filter, but with selectable cutoff frequency (below ODR/2 usually, it depends on the device you are using).

For example, for the LIS2DW12 accelerometer you can tune the bandwidth acting on BW_FILT[1:0] bit of  CTRL6 (25h) filter.

-Eleon

[VSavenia]

Thank you, Eleon!