High-pass path: BW_FILT setting

[user1]

When BW_FILT[1:0] = 00, it's different between AN5201 AND DATASHEET. Which one is real?

in AN5201:In Datasheet(DocID031788):

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[Eleon BORLINI · Accepted solution]

Hi @user1​ ,

Please consider that the two should refer to different signal paths, as shown in the below picture:

In particular, in the "application note" case, the HP filter path is considered: this means that when you select this path, and when you consider the BW_FILT[1:0] bit values (00 and 01), the band will be defined by the range [HP_filter_cutoff, ODR/4], and the upper value of this range will be always ODR/4.

In the "datasheet" case on the other side, you are considering the Low pass filter 2, or "LPF2" signal path, and in this case, if you select BW_FILT = 00bin, the resulting high frequency limit will be ODR/2, which is basically the maximum frequency according to the Nyquist theorem.

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-Eleon