AN4504 datasheet(13/41 Pages) STMICROELECTRONICS

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AN4504

Digital filters

The L3G4200D provides embedded low-pass and as well as high-pass filtering capability to

easily delete the DC component of the measured angular rate. As shown in Figure 2,

through the HPen, INTx_Sel and Out_Sel bits of CTRL_REG5, it is possible to

independently apply the filter on the output/FIFO data and/or on the interrupts data. This

means that it is possible to get filtered data while the interrupt generator works on unfiltered

data.

Figure 2. Low-pass/high-pass filter connections block diagram

4.1

Filter configurations

Referring to Table 8, the HPen and Out_Sel bits are used to drive unfiltered or filtered data

to the output registers and to the FIFO:

Table 7. CTRL_REG5 register

BOOT

FIFO_EN

HPen INT1_Sel1 INT1_Sel0

Out_Sel1

Out_Sel0

Table 8. HPen and Out_Sel settings

HPen

OUT_Sel1

OUT_Sel0

Description

Data in DataReg and FIFO are not high-pass filtered

Data in DataReg and FIFO are high-pass filtered

Data in DataReg and FIFO are low-pass filtered by LPF2

Data in DataReg and FIFO are high-pass and low-pass

filtered by LPF2

AN4504 データシート(PDF) 13 Page - STMicroelectronics