LDC2112: LDC2112 power-up calibration

Jakub Jedrzejewski

Part Number: LDC2112
Other Parts Discussed in Thread: LDC2114, LDC0851, LDC3114

Tool/software:

Hello,
I have an application where we check the presence of a metal target in front of the sensor LDC2112. We discovered the issue, that the sensor behaves differently depending whether the target was present or not during the power-up. Further investigation showed, that when there is a target during power-up, it seems that the sensor calibrates to it as a background level, and even a tiny increase in distance turns the output off, while it should be still on for a bit longer (when powering-up without the target). What can I do to mitigate that dependency?

9 days ago

0 Eddie LaCost 9 days ago

TI__Mastermind 43970 points

Hello Jakub,

This sounds like the baseline tracking function of the device. See section 8.1.9 of the datasheet for more information. If you power up with the target present, this will be used to determine the baseline measurement. On the LDC2114, there is no way to turn off baseline tracking. For a similar device, the LDC3114 also allows for "raw" mode where baseline tracking is disabled. If you are not looking to use baseline tracking, you could also look at the LDC131x and LDC161x or even LDC0851 for a simple switch type device.

0 Jakub Jedrzejewski 9 days ago in reply to Eddie LaCost

Prodigy 10 points

Is it possible to reset that tracking acquired during power-up? We have already manufactured dozen of PCBs with that chip, but it fails to operate when the target is present during power-up. I can remove the target and with fast tracking enabled it fixes itself, but I need to know if the target is present straight after the power-up of the sensor