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40
DM35425HR User’s Manual
𝐷
𝑛
=
𝐷
𝑛−1
×(2
𝑂𝑅𝐷𝐸𝑅
− 1) + 𝑁𝑒𝑤𝑆𝑎𝑚𝑝𝑙𝑒
2
𝑂𝑅𝐷𝐸𝑅
The response of the filter is shown in the Figure 9below. The Table below shows the -3dB cutoff for each of the filter settings. Both the figure
and the table are relative to the sample rate (f
s
).
Figure 9: Filter Response with each ORDER Value
ORDER -3 dB Cutoff
0
n/a
1
0.114791 * f
s
2
0.045995 * f
s
3
0.021236 * f
s
4
0.010255 * f
s
5
0.005042 * f
s
6
0.002501 * f
s
7
0.001246 * f
s
6.3.19
CH
N
_THRESH_STAT(R
EAD
/C
LEAR
)
This is the status register for the Threshold Detection. Reading a ‘1’ indicates that the threshold has been crossed. Writing a ‘1’ will clear the
bit.
B0:
‘1’ = Low Threshold has been crossed
B1:
‘1’ = High Threshold h
as been crossed
6.3.20
CH
N
_THRESH_ENA
(R
EAD
/W
RITE
)
This is the interrupts enable for the threshold detection. Bit defines are above. An interrupt is generated (if not already generated) each time a
sample is taken and the value is above the high threshold or below the low threshold.
6.3.21
CH
N
_THRESH_LOW
(R
EAD
/W
RITE
)
Signed 32-bit value indicating the low threshold. If the input signal drops below this value, an interrupt or clock can be generated until the
signal goes above this value. The 3 least significant bits are ignored from the actual threshold value.
