LDC1614: Coil Inductance

Janine Lin

Part Number: LDC1614

Dear Kristin,

You said 8 layers are not necessary. Does it mean, the value of coil inductance is not necessary to determine the sensing range? Is it the diameter of coil (dout)? I am using a coil diameter of 2 cm and our target sensing distance is 4 cm.

over 6 years ago

0 Kristin Jones93 over 6 years ago

TI__Genius 17440 points

Hi Janine,

That is correct: the coil's inductance does not affect the sensing range. The sensing distance for all LDC devices is based on the diameter of the sensor coil. The LDC1614 can detect targets at distances of at most 200% of the coil diameter. If you need to use a fast sample rate or you have a high noise floor, you may have difficulty sensing the target at 4cm using a 2cm coil.

Best Regards,

0 Janine Lin over 6 years ago in reply to Kristin Jones93

Expert 2190 points

Dear Kristin

Thank you for the quick response.

How to design a sensor coil with low noise floor?

0 Kristin Jones93 over 6 years ago in reply to Janine Lin

TI__Genius 17440 points

Hi Janine,

The LC tank is inherently a narrow band-pass filter, so it is immune to broadband noise. You can reduce the passband by increasing the Q factor of the LC tank. Equation 2 in the LDC1614 datasheet defines Q for the LC tank.

Additionally, minimizing the temperature shift of the sensors or using a reference sensor will help to reduce the noise floor. Otherwise, the noise floor heavily depends on the EMI in the sensor's environment and in the power and GND rails.

Best Regards,

0 Janine Lin over 6 years ago in reply to Kristin Jones93

Expert 2190 points

ok Kristin. Thank you.

Sensors

Sensors forum

LDC1614: Coil Inductance