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 - Configuring LDC2114 and LDC3114 Touch-Button Sensitivity

Erroneous or unintended button presses can result in a frustrating user experience in a human machine interface (HMI). Capacitive touch buttons trigger anytime a grounded object is brought close to the button; this can often cause false or erroneous button presses. One advantage mechanical buttons have over capacitive touch buttons is that a certain amount of force must be applied on the buttons for them to trigger. Button activation force for mechanical buttons is tuned by tightly controlling mechanical tolerances and precisely machining the moving parts, which is complex and expensive to achieve. Inductive touch buttons implemented using the LDC211x and LDC3114 devices can be configured to precise amounts of button activation force without the need for tight mechanical tolerances or moving parts. This application note provides instructions on how to configure the GAINn registers in the LDC211x and LDC3114 devices for configuring the button activation force.