Request for guidance on LPS25hb offset calibration - reg.

[ragu]

Hi, 

I am currently working with the LPS25HB chip, which performs well overall. 
However, once integrated into my device, I observed a consistent offset in the pressure readings. To address this, I applied an offset correction, and the readings became accurate. 

During initial testing with 15 devices, each unit required an individual offset adjustment. After applying these corrections, all devices reported pressure values within a similar range.
My device is enclosed in a circular case with a small opening positioned directly above the sensor. As I move toward mass production of over 1,000 boards, assigning offsets individually becomes a significant challenge. 
Based on my testing, it appears that offset calibration is mandatory. I would appreciate your guidance on how to streamline this process. 

Specifically:
Recommended steps to assign offsets efficiently during mass production
Any soldering guidelines, such as temperature considerations, to minimize offset issues
Suggestions for alternative sensor chips with similar specifications that may not require offset calibration.

PFA, the images showing the pressure values before and after applying the offset.
Your expertise and advice on this matter would be invaluable.

Any help would be appreciated. Thank you in advance for your support.

With Regards,

P. Ragu.

 

[Federica Bossi]

Hi ​@ragu ,

Based on the results you shared, the offset appears to be mainly related to the mechanical integration of the sensor into the final device rather than to sensor instability. Since each unit shows a different but repeatable offset, a one-point calibration after final assembly seems appropriate for mass production.

To minimize the issue, I recommend checking:

• the reflow/soldering profile against the datasheet recommendations
• any mechanical stress on the PCB or sensor caused by the enclosure
• the pressure vent/opening alignment and air path

If the offset remains significant after these checks, production calibration will likely be required. A newer sensor may help, but it will not fully remove the need for calibration if the mechanical design is the main cause.

[ragu]

Hi ​@Federica Bossi, 

Thank you for your detailed observations and recommendations. I appreciate your insights regarding the offset issue, which appears to stem from mechanical integration rather than sensor instability.

We will carefully review the recommended checkpoints, and your suggestion about considering newer sensors is noted. As you mentioned, calibration may still be necessary depending on the mechanical design.

Thank you once again for your valuable input.

With Regards,

P.Ragu