SNOA963B February   2020  – July 2021 LDC2112 , LDC2114 , LDC3114 , LDC3114-Q1

 

  1.   Trademarks
  2. 1Inductive Touch Buttons – The Working Principles
    1. 1.1 Target Distance (DTARGET) and Sensor Size
    2. 1.2 Target Material
    3. 1.3 Target Thickness
  3. 2LDC211x and LDC3114 Gain Settings
  4. 3Threshold Configuration Process
  5. 4Example Application
  6. 5Summary
  7. 6Revision History

1 Inductive Touch Buttons – The Working Principles

The three main components of the inductive touch button technology are the inductive sensor, target surface, and an inductance-to-digital converter. As shown in Figure 1-1 when a force is applied on the target surface, the material deflects slightly, reducing the distance between the inductive sensor and the target surface (DTARGET). This change in DTARGET changes the inductance of the sensor (Δ Sensor Inductance ∝ Δ DTARGET), which is measured by the inductance-to-digital converter. When the force is removed the surface returns to its original unstressed shape.

GUID-4A28847D-FE0C-482B-99F1-6B70AEFD330B-low.pngFigure 1-1 Inductive Touch Components

The primary factors that contribute to the sensitivity(1)of an inductive touch button are:

1. Button sensitivity is defined in terms of force that needs to be applied on the target conductive surface to trigger a response.