ASM330LHB chip shows large gyro bias jumps during temperature cycling (-40°C to 100°C)

[dayu]

I performed a temperature cycle check on the ASM330LHB chip. Relative to the warming process (red curve), during the cooling process (blue curve), it is prone to large zero-bias jumps (in the red box of the picture)。

The jump during the cooling process, I feel like there is a correction mechanism in the gyro in the chip, which recognizes a large shift in the gyro zero bias during the cooling process, and then immediately corrects the large zero bias shift.

Can you please help explain what causes this?

Note: These data on the image have been smoothed for 10 seconds.

[Federica Bossi]

Hi @dayu ,

That's very strange. Can you give me more details about your setup and your test?

Thanks.

[dayu]

We are putting 2 IMU chips on the same PCB. The temperature is lowered from about 30°C to -40°C, then raised from -40°C to 100°C, and then lowered from 100°C to about 30°C. The temperature is lowered at a rate of 1°C/min. The temperature is raised and lowered at a rate of 1°C/min. During the cooling process, large gyro bias jumps are likely to occur.

[Federica Bossi]

Hi @dayu ,

It could be something related to the soldering process that causes some stress to the mems.

[dayu]

Hi  @Federica Bossi 

But why does this large gyro bias jump only occurs during the cooling process and not during the warm up process?

[Federica Bossi]

Hi @dayu ,

I think it's chance, you might see it heating as well as cooling.