LPS25H Datasheet, PDF (40/45 Pages) STMicroelectronics – Embedded temperature compensation

Hardware digital filter
9
Hardware digital filter
LPS25H
An embedded digital filter is activated by selecting the FIFO_MEAN_MODE and
WTM_POINT (FIFO_CTRL(2Eh)) and activating the FIFO_EN.
The digital filter reduces the pressure noise level to 0.010 hPa rms (1pa at 1 sigma) and
allows to reduce the internal ADC HW average reducing the power consumption keeping
the same pressure noise level.
Figure 13. Hardware digital filter
V oltage
R ef erenc e
AFE
Te m p e ra tu re
S en sor
A nalog blocks
ADC
Qu adratic
Te m p e ra tu re
com pen sation
P
t
C om pensation
C oeffic ients
M em ory
Tem perature
co m p e ns atio n
PR ESS_O U T _XL
PR ESS_O U T _L
PR ESS_O U T _H
F
I
F
Average 1 H z
O
F IF O_EN
F IF O M OD E
F IF O_M EN _D EC
E m b e d de d
filte r
9.1
Filter enabling and suggested configuration
To reduce the internal pressure and temperature average the configuration below can be
used:
RES_CONF (10h) = 05h
FIFO_CTRL (2Eh) = C0
CTRL_REG2 (21h) = 40h
In this way, the power consumption at 1 Hz is reduced from 25 µA (typical) to 4.5 µA (typical)
with a pressure noise of 0.01 hPa rms
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