The ODR is channel specific, which means that one channel
can have one ODR, while another channel can have the same
or a different ODR.
Note that these ODRs are meant for a single channel con-
version; the ODR needs to be divided by n for n channels
scanning. For example, if the ADC were running at 214.65
SPS and four channels are being scanned, then the ODR per
channel would be 214.65/4 = 53.6625 SPS.
16.1.7 Digital Filter
The LMP90xxx has a fourth order rotated sinc filter that is used to configure various ODRs and to reject power supply frequencies
of 50Hz and 60Hz. The 50/60 Hz rejection is only effective when the device is operating at ODR ≤ 13.42 SPS. If the internal CLK
or the external CLK of 3.5717 MHz is used, then the LMP90xxx will have the frequency response shown in Figure 5 to Figure 9.
0 12 24 36 48 60 72 84 96 108 120
-120
-100
-80
-60
-40
-20
0
GAIN (dB)
FREQUENCY (Hz)
1.6775 SPS
3.355 SPS
30139560
FIGURE 5. Digital Filter Response, 1.6775 SPS and 3.355 SPS
0 12 24 36 48 60 72 84 96 108 120
-120
-100
-80
-60
-40
-20
0
GAIN (dB)
FREQUENCY (Hz)
6.71 SPS
13.42 SPS
30139573
FIGURE 6. Digital Filter Response, 6.71 SPS and 13.42 SPS
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LMP90100/LMP90099/LMP90098/LMP90097
