LIS3DH ODR vs System Bandwidth Clarification

[Louie Francis Ouano]

Posted on May 22, 2018 at 11:40

On Section 3.2.1 of the datasheet(DocID17530 Rev 2), there is a column in Table 10 called 'BW[Hz]', this is the 'system bandwidth'. The datasheet does not discuss more details on what the 'system bandwidth' means but I'm assuming this indicates the real output data rate. Is this correct?

So going back to Table 10, if I am configuring LIS3DH into High-resolution mode and an ODR of 400Hz the BW is ODR/9. If my above assumption is correct, this would mean that the real output rate is actually 44Hz(i.e.,400/9)?

Thanks.

[Miroslav BATEK]

Posted on May 22, 2018 at 20:52

You assumption is not correct. The system bandwith means the frequency of the acceleration which is attenuated by 3dB. You imagine it as filter.

All frequency componets of the measured acceleration above the BW will be attnuated.

The output data rate is still the one which you select it doesn't change with the BW.