LDC1312: Optimise flexi sensor to fit LDC1312 parameters

james lawrence19

Part Number: LDC1312

Hi There,

I've designed a number of different layouts of flexi circuit sensors and experiencing difficulties getting both the sensor frequency and the Rp values within the spec of the datasheet. If I reduce the sensor frequency then the Rp goes down too. Is there anything I can do to compensate please? e.g. I've got sensor frequency of 11.3 MHz and Rp of 20R

Thanks in advance!

over 6 years ago

0 Luke LaPointe over 6 years ago

TI__Genius 13335 points

Hello,
Can you post the parameters you are using for your coil design? Specifically, the coil diameter, trace width/spacing, number of turns, number of layers, spacing between layers, and copper thickness?
Typically you can improve Rp by decreasing Rs, decreasing C, or increasing L. If you are limited by C due to the frequency and L due to the geometry, you can still decrease the Rs by increasing the copper thickness (going from 1/3 oz copper to 1/2 oz copper for example). Additionally you can add a series inductor, but there will be some sensitivity loss because you will be dividing the inductance change across a fixed inductor. Refer to the following blog for more info: e2e.ti.com/.../inductive-sensing-how-to-use-a-tiny-2mm-pcb-inductor-as-a-sensor
Thanks!
Luke

0 james lawrence19 over 6 years ago in reply to Luke LaPointe

Prodigy 30 points

Thanks Luke, this helped!

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LDC1312: Optimise flexi sensor to fit LDC1312 parameters