High-pass filter

AN2989

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Doc ID 15761 Rev 1

4

High-pass filter

The LIS331DLM provides embedded high-pass filtering capability to easily delete the DC

component of the measured acceleration. As shown in Figure 5, it is possible to

independently apply the filter on the output data and/or on the interrupts data through the

FDS, HPen1 and HPen2 bits of the CTRL_REG2 register configuration. This means that it is

possible, for example, to obtain filtered data while interrupt generation works on unfiltered

data.

Figure 5.

High-pass filter connections block diagram

4.1

Filter configuration

As shown in Table 12, two operating modes are possible for the high-pass filter:

:

The bandwidth of the high-pass filter depends on the selected ODR and on the settings of

Table 13.

Table 12.

High-pass filter mode configuration

HPM1

HPM0

0

0

Normal mode (reset reading HP_RESET_FILTER)

0

1

Reference mode

1

0

Same as configuration 00h

1

1

Not allowed