LIS3DH Anti-aliasing

[kevinblain9]

Posted on June 20, 2016 at 12:44

Does anyone have any characteristics for the AA filter and method on the LIS3DH accelerometer?

E.g. slope, number of poles, type...ThanksKevin #lis3dh

[Simon Wyss]

Posted on May 11, 2017 at 09:20

Does anyone know something about the used anti-aliasing filter?

Does the filter change if he ODR (Output Data Rate) is changed? The datasheet tells me YES.

measured 19.8 Hz with the 100 Hz ODR.

The anti-aliasing filter doesn't work as required. It should block frequencies above 50 Hz.

The correct frequency is marked red below (sweep from 14 Hz to 19.8 Hz, later constant 19.8 Hz):

Are there informations concerning the characteristic of the anti-aliasing filter?

If the filter is always the same (setup for the fastest data rate), then the lower ODR are not useful.

Do I have to use much higher data rates for measuring 19.8 Hz without errors from aliasing? 

[Simon Wyss]

Posted on May 18, 2017 at 23:28

Any news on the anti-aliasing filter characteristics?

[Simon Wyss]

Posted on May 21, 2017 at 16:01

Got the answer thanks to the very clearly and user friendly written datasheet:

On Page 12 is written'System Bandwidth: ODR/2'with a hint to go to Table 25 where this value changes depending of the resolution mode:

Low-power (8-bit): Bandwidth: ODR/

2

normal mode (10-bit): Bandwidth: ODR/

2

High-res (12-bit): Bandwidth:

ODR/

9

I got the 'error' with the aliasing because I used the High-res mode, which led to 4.5 times lower Bandwidth (than I thought).