2020-10-26 05:48 AM
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.
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2020-10-26 08:58 AM
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
2020-10-26 08:58 AM
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
2020-10-26 11:32 PM
Ok, and what about LPF2 filter, what type is it?
2020-10-27 01:51 AM
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
2020-10-27 03:27 AM
Thank you, Eleon!