LIS3DH Self Test

[greenanttech]

Posted on October 30, 2013 at 12:48

Dear all,

I am working on the LIS3DH and trying to correctly develop the embedded Self Test feature.All I do is evaluating the difference between the ''Normal Measurements'' and the ''Self Test Measurements'' and check if these differences match with the Self Test Output Change declared at page 10 in the Data Sheet.The problem is that (@3V supply) I always get values about one half the ones indicated in the data sheet. I also found this Self Test Procedure on the web:

http://www.edn.com/design/analog/4390843/2/The-embedded-self-test-feature-in-MEMS-inertial-sensors

and it underlines that the measured difference should fall between a range of values but I cannot find on the Data Sheet the MIN/MAX values for the SELF TEST OUTPUT CHANGE.Considering that it also depends on the power supply, how can I evaluate this MIN/MAX value for my application working between 3.6V and 2.5V??Waiting for you reply,Best regards,Claudio #lis3dh-self-test

[Thiago REIS]

Posted on November 19, 2013 at 15:24

Hello Claudio,

LIS3DH accelerometer self-test min/max values are: min_x = min_y = min_z = 60mg and max_x = max_y = max_z = 1700mg. At +/-2g FS, this translates to 60LSBs min and 1700LSBs max values because the sensitivity is 1mg/LSB. This min/max range covers all Vdd from 1.71V to 3.6V, all FS ranges and all ODRs. Please let me know if this was the information that you were looking for. Thank you, Thiago Reis

[Mich1]

Posted on May 19, 2014 at 15:44

Hello Thiago,

I do not understand your answer => in the datasheet it is written 276 LSb for X and Y, and 984 LSb for Z axis. How do you justify your answer? Best Regards. Mich.