LDC1612: AC magnetic field effect

RAMAKRISHNA NAGARAJU GUDLA

Prodigy 155 points

Part Number: LDC1612
Other Parts Discussed in Thread: LDC1101

Hello TI Experts,

Greetings!!!

The datasheet of LDC1612 says “immunity to DC magnetic Fields and Magnets”.

But it did not specify the immunity to AC currents / AC magnetic Fields.

For example the target carries the current with frequency of 1.5MHZ, I am curious how it will effect the inductive sensor placed near the target.

Will it be different with LDC1101 ?

Please share your thoughts.

Thanks and Regards

G R K Nagaraju

over 6 years ago

0 Bala Ravi over 6 years ago

TI__Expert 6625 points

Hi Ramakrishna,
We've got your request. We will get back to you as soon possible.

Best Regards,
Bala Ravi

0 Clancy Soehren over 6 years ago

TI__Mastermind 23810 points

The LDC1612 and LDC1101 will work in the same way. An AC field may impact the measurement, but you can test the EVM to verify the effects.

0 RAMAKRISHNA NAGARAJU GUDLA over 6 years ago in reply to Clancy Soehren

Prodigy 155 points

Hi,

Thanks for reply.

With a 60uH sensor coil, we could see only 800nH as a margin.

We worried if the margin works with the AC field.

Can you plesae share your thoughts.

Thanks

0 Clancy Soehren over 6 years ago in reply to RAMAKRISHNA NAGARAJU GUDLA

TI__Mastermind 23810 points

For margin, are you referring to your signal strength? By 800nH, are you referring to your desired resolution?

To increase the signal strength, you can:

- increase the size of the LDC coil (not necessarily the inductance). The coil size should not be bigger than your target however
- increase the range of motion
- use reference coil to compensate for temperature drift

Also please take a look at this EMI app note for components to include in your design to help mitigate these effects:

www.ti.com/.../snoa962

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LDC1612: AC magnetic field effect