LDC1614: at high temperature

Janine Lin

Expert 2190 points

Part Number: LDC1614

Dear Bala and Clancy,

We tested the LDC1614evm at different temperature, as the temperature increases as will as inductance.

My question is how to keep the inductance value the same even at different temperature? Please see the data below.

Thank you.

Temperature Testing_(中心6mm) 直角 (Rectangle).xlsx

over 6 years ago

0 Clancy Soehren over 6 years ago

TI__Mastermind 23810 points

Janine,

That is normal behavior. There are several contributors to this effect:
- temperature drift of oscillator (internal or external)
- capacitor drift over temperature. We recommend using C0G capacitors for this reason.
- PCB sensor coil temperature drift. This should be a smaller effect than the previous two.

You can minimize the temperature drift by using the above steps; however, to complete remove it, then an extra channel must be used as a reference sensor. The reference sensor will see the same temperature drift as your measurement sensors, so it can be used to remove temperature drift.

0 Janine Lin over 6 years ago in reply to Clancy Soehren

Expert 2190 points

Thank you for the recommendation Clancy. How to do the differential configuration? In the datasheet , i only see a single ended configuration.

0 Clancy Soehren over 6 years ago in reply to Janine Lin

TI__Mastermind 23810 points

For inductive sensing, differential means using two channels and comparing the results between them. The comparison must be done in the MCU.

0 Janine Lin over 6 years ago in reply to Clancy Soehren

Expert 2190 points

Ok Clancy, got it. Thank u.

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LDC1614: at high temperature