ADXL346 - While the sensor noise itself has a Gaussian distribution, wouldn’t this distribution be impacted by quantization ? How do we estimate similar probability distribution for the noise after quantization ?

ADXL346 - While the sensor noise itself has a Gaussian distribution, wouldn’t this distribution be impacted by quantization ? How do we estimate similar probability distribution for the noise after quantization ?

Hi Eladi,

The XL346 resolution is 4mg/LSB. Quantization noise for an ideal converter is LSB/sqrt(12) rms, or about 0.3 LSB rms. For the XL346, the quantization noise is therefore about 1.1mg rms.

The noise as shown in figure 54 of the data sheet is always greater than 0.3 LSB rms, so the XL346 is not limited by quantization noise.

The noise measurements in figure 54 were taken using the digital output, so they include the effects of quantization.

Regards,

Howard

Hi Eladi,

The XL346 resolution is 4mg/LSB. Quantization noise for an ideal converter is LSB/sqrt(12) rms, or about 0.3 LSB rms. For the XL346, the quantization noise is therefore about 1.1mg rms.

The noise as shown in figure 54 of the data sheet is always greater than 0.3 LSB rms, so the XL346 is not limited by quantization noise.

The noise measurements in figure 54 were taken using the digital output, so they include the effects of quantization.

Regards,

Howard