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Visitor II
February 27, 2021
Solved

LSM6DSM gyroscope random walk, bias stability

  • February 27, 2021
  • 7 replies
  • 4595 views

The random walk and bias stability of the LSM6DSM gyroscope could not

be found in the data sheet.

Random walk , bias stability of gyroscope Please tell me the reference value.​

    This topic has been closed for replies.
    Best answer by Eleon BORLINI

    Hi @totaw.1​ ,

    AVAR parameter are not fully tested in the inline tester production, that's why they are not in the datasheet with upper and lower spec limits.

    I can however share bench results on a representative sample, tested in the following conditions:

    VDD = 1.8V

    VDDIO = 1.8V

    ODR XL = 208Hz HP

    ODR Gyro = 208Hz HP

    Synchronous reading

    Temperature Range -40 ÷ 85DegC

    Angular random walk of gyroscope:

    0693W000007ZjWoQAK.pngBias stability of gyroscope:

    0693W000007ZjWyQAK.pngIf my reply answered your question, please click on Select as Best at the bottom of this post. This will help other users with the same issue to find the answer faster.

    -Eleon

    7 replies

    ST Employee
    March 1, 2021

    Hi @totaw.1​ ,

    AVAR parameter are not fully tested in the inline tester production, that's why they are not in the datasheet with upper and lower spec limits.

    I can however share bench results on a representative sample, tested in the following conditions:

    VDD = 1.8V

    VDDIO = 1.8V

    ODR XL = 208Hz HP

    ODR Gyro = 208Hz HP

    Synchronous reading

    Temperature Range -40 ÷ 85DegC

    Angular random walk of gyroscope:

    0693W000007ZjWoQAK.pngBias stability of gyroscope:

    0693W000007ZjWyQAK.pngIf my reply answered your question, please click on Select as Best at the bottom of this post. This will help other users with the same issue to find the answer faster.

    -Eleon

    Visitor II
    March 23, 2021

    Is there a unit problem of Angular random walk of gyroscope in your answer ?

    I expected the data in "deg/s /sqrt(Hz))" or in deg/sqrt(h) ?

    totaw.1Author
    Visitor II
    March 2, 2021

    Thank you very much.

    When VDD = VDDIO = 3.3V, does the value change considerably?

    ST Employee
    March 2, 2021

    Hi @totaw.1​ ,

    yes, values of these parameters are basically constant across the device Vdd/VddIO range.

    The main parameter that may change is the current consumption, slightly increasing with the Vdd.

    -Eleon

    totaw.1Author
    Visitor II
    March 2, 2021

    Thank you very much.

    I understand.

    totaw.1Author
    Visitor II
    March 4, 2021

    Sorry do you have data on random walk and bias stability for lsm6d3h?

    (ODR=1.66kHz 2000dps)

    I need lsm6dsm and lsm6d3h gyroscope random walk and bias stability data.​

    ST Employee
    March 4, 2021

    Hi @totaw.1​ ,

    AVAR parameters don't change too much with respect to the ODR, so they are pretty similar from ODR 208Hz to 1.66kHz. They also slightly differ between the two sensor families.

    However, we currently don't have the AVAR at maximum gyro FS, since they are typically tested at the lower FS to appreciate the lowest detectable variations in the signal. In theory, the parameter should have the same value also for higher FSs, but I cannot guarantee at practical level.

    -Eleon

    totaw.1Author
    Visitor II
    March 5, 2021

    I am always grateful for your help

    I'm sorry, this is the last question.

    Is there any data on the acceleration bias Repeatability  and scale factor Repeatability  ( / year ) of LSM6DSM?

    ST Employee
    March 5, 2021

    Hi @totaw.1​ ,

    thank you first for your appreciation.

    About the "acceleration bias repeatability" parameter you might consider the standard deviations shown in the above picture: they accounts for a confidence interval of

    About the "scale factor repeatability" over year, which I interpret as the change / drift in sensitivity across 1 year, you can consider the ±1% sensitivity tolerance that you can find in the datasheet, p.23.

    -Eleon

    Visitor II
    March 23, 2021

    Is there a unit problem in the Angular random walk of gyroscope ?

    I expected a value in °/s /sqrt(Hz) or in °/sqrt(h) ?

    ST Employee
    March 23, 2021

    Hi @NPoth.1​ ,

    yes, you are right, there is a typo in the pictures above.

    Thank you for the notification.

    -Eleon