LDC1612 / Several minutes is required to stabilize inductance output

Hello Sonoki-san,

Please make sure that there are no thermal gradients in the environment. Also, check to see if the sensor signal amplitude is correct; if not, try changing the sensor current drive setting. You may want to upgrade to the new GUI which is available for download; it is an improvement over the version you are currently using.

Regards,

Chris O

Hi Chris,

Thank you for your comment.

Do you think there is possibility that the output will be drifted by self heat up by self-heating calculated with Vdd x Idd?

I attached additional data that is inductance log data when changed position of target. It shows the output is stable when changed position of target. So I think the output data will be drifted after power-up due to self-heating.

LDC1612EVM_Changed position of target.pdf

Best Regards,

Sonoki

Hi Chris,

Here is the additional data on my bench.

LDC1612 was re-powered on after powered off immediately, but then the output was stable after re-powered on.

Inductance log_Power off and re-power on immediately.pdf

Best Regards,

Sonoki

Hi Chris,

I'm sorry to press you but I'm waiting for your comment.

Best Regards,
Sonoki

Hello Sonoki-san,

If the target is very close to the sensor, it could actually see a small heating effect from the eddy currents. While this effect is small, the LDC161x devices are sensitive enough to measure it.

Regards,

ChrisO

Hi Chris,

Thank you for your comment. I understand that it can be seen small heating effect from the eddy currents when target is very close to sensor. However in my case the data I attached was measured with no target. How do you think about it? I also think this is very small drift so it may not make an impact for measurement, but I need to explain the reason of this small drift without target.

Best Regards,
Sonoki

Hello Sonoki,

You can actually have a small amount of self-heating of the sensor itself.

Regards,

ChrisO