Datasheet

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
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
LMP90100
www.ti.com SNAS510P –JANUARY 2011–REVISED MARCH 2013
Note that these ODRs are meant for a single channel conversion; 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.
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 37 to Figure 41.
Figure 37. Digital Filter Response, 1.6775 SPS and 3.355 SPS
Figure 38. Digital Filter Response, 6.71 SPS and 13.42 SPS
Copyright © 2011–2013, Texas Instruments Incorporated Submit Documentation Feedback 25
Product Folder Links: LMP90100