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Why two LPF on LSM9DS1?

SBern.2
Associate

For the gyro at least, LPF1 is not an anti-aliasing filter (https://community.st.com/s/question/0D53W00000Ac1obSAB/is-it-true-that-the-gyro-of-the-lsm9ds1-has-the-lpf1-low-pass-filter-after-the-adcthis-design-will-suffer-from-aliasing-not)

Perhps for the acceleromter it is an AAF?

In general, I'm unclear about why there are two LPF.

1 ACCEPTED SOLUTION

Accepted Solutions
Eleon BORLINI
ST Employee

Hi @Community member​ ,

specifically for the gyro, the first LPF is basically reducing the high-frequency noise coming from the ADC conversion step (that are coming from the inner electronics, and ), while with the second LPF filter you can tune the sensor band (and related integral noise) for specific applications that don't require the high-frequency component of the spectrum (for example, the free fall or the 6D/4D position detection).

For the accelerometer the LPF1 filter is more indicated for the anti-alias purpose.

-Eleon

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1 REPLY 1
Eleon BORLINI
ST Employee

Hi @Community member​ ,

specifically for the gyro, the first LPF is basically reducing the high-frequency noise coming from the ADC conversion step (that are coming from the inner electronics, and ), while with the second LPF filter you can tune the sensor band (and related integral noise) for specific applications that don't require the high-frequency component of the spectrum (for example, the free fall or the 6D/4D position detection).

For the accelerometer the LPF1 filter is more indicated for the anti-alias purpose.

-Eleon