2025-06-05 1:23 AM
Hi ,
I see that the bandwidth of IIS2DLPC is 3200 Hz for low power mode 1 according to the datasheet (page 22 ). Also it mentions that the maximum ODR is 200 Hz for this mode. This looks contradictory to me as 3200Hz bandwidth won't be compatible with 200Hz output data rate.
Could you please explain what exactly does this mean?
Best regards,
Kev
Solved! Go to Solution.
2025-06-05 1:36 AM
The bandwidth determines the cutoff frequency of the analog low-pass filter inside the accelerometer. This filter ensures that unwanted high-frequency noise or motion doesn’t alias into your desired signal bandwidth.
The ODR determines how often this filtered signal is sampled and sent out via I²C/SPI.
So in Low Power Mode 1:
The analog front-end can respond to signals up to 3200 Hz.
But the digital system only samples at up to 200 Hz, meaning you won’t observe any signal detail above 100 Hz (due to the Nyquist limit), and aliasing will occur unless analog filtering is applied.
2025-06-05 1:20 AM - last edited on 2025-06-05 1:40 AM by Andrew Neil
Duplicate - merged.
Hi ,
I see that the bandwidth of IIS2DLPC is 3200 Hz for low power mode 1 according to the datasheet (page 22 ). Also it mentions that the maximum ODR is 200 Hz for this mode. This looks contradictory to me as 3200Hz bandwidth won't be compatible with 200Hz output data rate.
Could you please explain what exactly does this mean?
Best regards,
Kev
2025-06-05 1:36 AM
The bandwidth determines the cutoff frequency of the analog low-pass filter inside the accelerometer. This filter ensures that unwanted high-frequency noise or motion doesn’t alias into your desired signal bandwidth.
The ODR determines how often this filtered signal is sampled and sent out via I²C/SPI.
So in Low Power Mode 1:
The analog front-end can respond to signals up to 3200 Hz.
But the digital system only samples at up to 200 Hz, meaning you won’t observe any signal detail above 100 Hz (due to the Nyquist limit), and aliasing will occur unless analog filtering is applied.
2025-06-05 1:49 AM
So the bandwidth mentioned in the table is the bandwidth of the analog front end and not the final bandwidth of the sensor in that particular setting.