LDC1612: LDC1612 inquiry

Marvn Arcangel

Part Number: LDC1612

Hi Team,

For a short-range LD1612 based target detection sensor, where the target would be a 3 mm diameter x 1 mm thick copper metal surface that would never be any further than ~1 mm away from the coil, where this coil would be the Type “N” Reference Coil (3 mm diameter, 3 turns per layer, 4 layers, 4 mil trace width and space). Also, what would be the most appropriate tank circuit components, L (inductor) and C (capacitor), for uses onboard the Type “N” Reference Coil PCB, and what LDC1612 register values setting would best optimize the LDC1612 for such a single coil (Ch0 only) sensor where there’s really no need for fast sampling.

Regards,

Marvin

18 days ago

0 Eddie LaCost 17 days ago

TI__Mastermind 44625 points

Hello Marvin,

Please see the blog post below. Unfortunately, it was removed from the web, but you can still access it using wayback machine. This coil is very similar to "N" and you should be able to use the same component values. You may also want to experiment with using a smaller series inductor to improve sensitivity. 3.3uH may be a good place to start.

https://web.archive.org/web/20171021025819/https://e2e.ti.com/blogs_/b/analogwire/archive/2014/06/10/inductive-sensing-how-to-use-a-tiny-2mm-pcb-inductor-as-a-sensor

To optimize the performance, I recommend following the app note below to set the idrive for the appropriate signal level. Additionally, you should set RCOUNT to the maximum value. Finally, be sure that the deglitch filter is set properly. This should be set to the frequency that is closest to your resonant frequency without being lower. For example, if you have a 6MHz resonant frequency, you should set this to 10MHz. I also included an app note that discusses optimizing resolution below.

https://www.ti.com/lit/an/snoa950/snoa950.pdf

https://www.ti.com/lit/an/snoa944/snoa944.pdf

Sensors

Sensors forum

LDC1612: LDC1612 inquiry