Texas Instruments LDC1000EVM - Evaluation Module for Inductance to Digital Converter with Sample PCB Coil LDC1000EVM LDC1000EVM 사용자 설명서

제품 코드

LDC1000EVM

Interfacing Different Sensor Coils

Getting a custom sensor to operate with LDC1000

1. Break off EVM coil along perforation

2. Connect custom sensor coil and capacitor (C) to J2 on the EVM (Fig. 2)

Steps to pick C:

a. Calculate / measure inductance of the coil (L)
b. Calculate / measure resistance of the coil (R

)

c. Pick C value to satisfy

both conditions below:

Resonance frequency between
5 kHz to 5 MHz:

Resonance impedance (R

) between

798 Ω to 3.93 MΩ:

Note: If L is not large enough, add discrete inductor in series with sensor

3. Plug EVM into host and ensure GUI indicates EVM connection

4. GUI settings

Update

Sensor Capacitor value on GUI configuration page to

the chosen value of C

Program

Sensor Frequency register: value should be 20% below

sensor’s resonant frequency

Program

LDC Configuration register:

Amplitude: 4V
Response time: 6144 cycles

Determine

Rp_MAX and Rp_MIN register values:

   Set Rp_MIN to minimum value = 0.798 kΩ
   Set Rp_MAX to maximum value = 3926.991 kΩ
   START data capture. Check “Proximity Data” value.

LDC1000EVM Quick Start Guide

Texas Instruments 2013

Note: If “Proximity Data” equals 0, add a discrete inductor in series to the sensor coil

to get into the operating range of the LDC

J2 connector block

Fig.2 Custom coil connection

Note: On the streaming screen (Fig. 1), make sure to STOP data capture when making

changes to register settings and START data capture to apply the changes

RES

2*pi*√LC