Hi, everybody!

Here is my question:

With my ADIS16375, I use DIO1 as a 2kHz Sync clock input, DEC_RATE set as 100, so how can I calculate the noise variance of Gyro and Accelerometer output according to the datasheet? How to use parameters like "Output Noise", ''Rate Noise Density", etc?

• Hi,

Accelerometer Specifications - Quick Definitions | Analog Devices
As for using the Output Noise Parameter, this means that your measured signal must not fall below this value as it being too small would make it seem that that signal is also just noise.

As an example:

This image shows an acceleration with peak of 0.1 g. The noise in the figure corresponds to the output noise found in the data sheet which is measured to be 1.5mg (rms).

As seen in the figure, the acceleration can still be distinguished from the noise.

When the acceleration now has a peak less than the output noise, (1mg peak) it is seen that the acceleration is fully enveloped with noise.

I hope that this has given you an overview on this topic.

Regards,

JP

• In addition to what John.Tuazon offered, you can estimate the noise using the following formuka:

Noise = noise-density x sqrt(1.57 x ODR)

ODR = output data rate

When you say that DEC_RATE = 100, is that in decimal, binary or hexadecimal?

Let's assume it is in binary for this case, but please correct me if that is not correct

ODR = input clock/(DEC_RATE + 1)

ODR = 2000/(4+1) = 400 SPS

• Thank you, the explaination help me a lot to understand the accelerometer specifications!

• Thanks a lot, it ireally helps with my application!

BTW, DEC_RATE is 100 in decimal. I will note that clearly next time!