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    Why the power spectral density(PSD) of BMI088 Gyro(x/y/z) have strange peak point?

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    Community Moderator

    Re: Why the power spectral density(PSD) of BMI088 Gyro(x/y/z) have strange peak point?

    Hi Silva,

    The gyro noise level is not related to full scale range. It is only correlative with the bandwidth setting. This means that the typical noise density of 0.014dps/rt(Hz) applies to all full scale ranges.

    Thanks.

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    Member

    Re: Why the power spectral density(PSD) of BMI088 Gyro(x/y/z) have strange peak point?

    Hi FAE_CA1,

    Thank you for your help.

    For the noise amplitude, I will keep looking into it.

     

    For the spikes in PSD, the data files are attached. To recover PSD at low frequency, I have to log the data for a long time. I attached part of my log files. From these files, you will be able to see spikes at low frequency when 230Hz LPF is chosen.

     

    Thanks.

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    Member

    Re: Why the power spectral density(PSD) of BMI088 Gyro(x/y/z) have strange peak point?

    Hi FAE_CA1,

    Today, I tested the noise level of Bosch shuttle board of BMI055. And you are right about that the noise level is not related to gyro range.

    However, the noise amplitude is still very large (+/-10dps max). Please see the screenshot below. Do you have any clue?

    Thank you.

    bmi088_125dps_2000Hz_523Hz.png

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    Community Moderator

    Re: Why the power spectral density(PSD) of BMI088 Gyro(x/y/z) have strange peak point?

    This PSD issue with big jitter found on x/y axis is confirmed from our engineer team and it is understood. 

    The root cause is the digitial noise coming from the ADC module insdie our ASIC of sensor.  

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    Member

    Re: Why the power spectral density(PSD) of BMI088 Gyro(x/y/z) have strange peak point?

    Hi Vincent,

    Thank you for confirmation. This PSD issue doesn't affect much. We can choose 523Hz LPF and apply our own filter.

    However, do you have any clue about the noise issue in my previous post? According to the datasheet and FAE_CA1, the noise amplitude should be within +/-3dps. What I get is more than +/-10dps. This will affect the ARW (angle random walk) and cannot be improved by a LPF.

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