AN2847 datasheet(18/31 Pages) STMICROELECTRONICS

Part #	AN2847

Description	This document provides application information for the low-voltage 3-axis digital output

PDF	31 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

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18 / 31 page

High pass filter

AN2847

18/31

Doc ID 15136 Rev 2

4.1.1

Normal mode

In this configuration the high-pass filter can be reset by reading the HP_FILTER_RESET

Figure 6.

HP_FILTER_RESET readings

4.1.2

Reference mode

In Reference mode configuration the output data is calculated as the difference between the

input acceleration and the content of the REFERENCE register. This register is in 2’s

complement representation and the value of 1LSB of these 7-bit registers depends on the

selected full scale (

Table 14).

Table 13.

High-pass filter cut-off frequency configuration

HPcoeff2,1

ft [Hz]

Data rate = 50 Hz

ft [Hz]

Data rate = 100 Hz

ft [Hz]

Data rate = 400 Hz

ft [Hz]

Data rate = 1000 Hz

0.5

0.25

0.5

0.125

0.25

2.5

Table 14.

Reference mode LSB value

Full scale

Reference mode LSB value (mg)

2~16

4~31

8~63

AN2847 Datasheet(PDF) 18 Page - STMicroelectronics