SNOA993A June   2018  – July 2021 LDC2112 , LDC2114 , LDC3114 , LDC3114-Q1

 

  1.   Trademarks
  2. 1Introduction
  3. 2Scan Rate and Sampling Interval
    1. 2.1 Low Power Mode and Normal Power Mode
    2. 2.2 Button Sequencing and Error Handling
  4. 3Data Polarity and Timeout
    1. 3.1 Button Timeout
  5. 4Internal Algorithms Overview
  6. 5Baseline Tracking
    1. 5.1 Baseline Increment
    2. 5.2 Baseline Tracking Reset
    3. 5.3 Button Actuation Time
    4. 5.4 BTPAUSE
    5. 5.5 Fast Tracking Factor
  7. 6Gain, Hysteresis, and Threshold
    1. 6.1 Threshold and Hysteresis
  8. 7Multi-Button Algorithms
    1. 7.1 Max Win
    2. 7.2 Anti-Common Mode
    3. 7.3 Anti-Twist Factor
    4. 7.4 Anti-Deform Factor
  9. 8Summary
  10. 9Revision History

1 Introduction

The Texas Instruments LDC211x and LDC3114 devices can monitor changes in a sensor resonant frequency to determine whether a stimuli corresponds to a user interaction such as a button press. Refer to the Inductive Touch System Design Guide for HMI Button Applications application report for details on how to construct a mechanical system suitable for inductive sensing button applications, sensor design guidance, and an overview of device configuration. The LDC211x and LDC3114 use several internal algorithms to compensate for environmental shifts, determine whether the sensor signal change corresponds to a button press, and also to correct for mechanical cross-talk between multiple buttons. This document details the operation and configuration of the algorithms.