SNOA954D November   2019  – June 2021 LDC0851 , LDC1001 , LDC1001-Q1 , LDC1041 , LDC1051 , LDC1101 , LDC1312 , LDC1312-Q1 , LDC1314 , LDC1314-Q1 , LDC1612 , LDC1612-Q1 , LDC1614 , LDC1614-Q1 , LDC2112 , LDC2114 , LDC3114 , LDC3114-Q1

 

  1.   Trademarks
  2. 1LDC Applications
    1. 1.1 Axial Sensing
      1. 1.1.1 Buttons and Keypads
    2. 1.2 Event Counting
    3. 1.3 Other Types of Sensing
  3. 2Inductive Sensing Theory of Operation
  4. 3LDC Device Feature Overview
    1. 3.1 Sample Rate
    2. 3.2 Sensor L Measurement and Reference Frequency
    3. 3.3 Sensor RP Measurement
    4. 3.4 Sensor RP (Current) Drive Capability
    5. 3.5 Switch Output Functionality
    6. 3.6 Sensor Frequency Range
    7. 3.7 Multi-Channel Sensing
    8. 3.8 Power Management
    9. 3.9 Internal Algorithms
  5. 4Device Families
    1. 4.1 Inductive Touch Devices
      1. 4.1.1 Inductive Touch LDC Recommended Applications
    2. 4.2 Multichannel LDC Devices
      1. 4.2.1 Multi-Channel LDC Recommended Applications
      2. 4.2.2 LDC1101
        1. 4.2.2.1 LDC1101 Recommended Applications
      3. 4.2.3 LDC0851
        1. 4.2.3.1 Recommended Applications
  6. 5Summary
  7. 6Revision History

Buttons and Keypads

The axial sensing configuration can be used for human-machine interface (HMI) applications such as buttons or keypads using continuous metal surfaces. By attaching a metal film as thin as 10 µm to the inside surface, Inductive touch buttons can be constructed with non-conductive materials such as glass, plastic, and even wood. This type of implementation can be used for rugged, waterproof, long-life interfaces which can work in harsh environments where other technologies fall short. Details on one implementation of this capability can be found at Touch on Metal Buttons Reference Design, which uses the LDC1614.

Some LDC devices, such as the LDC2114, include algorithms and output features that make them drop-in replacements for currently existing mechanical implementations and simplify software design. For more information on these algorithms, see the LDC2112 and LDC2114 Internal Algorithm Functionality application report.

Another example which uses LDC sensing to create more reliable snap-dome switches can be found at 16-Button Inductive Keypad.