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 (D_TARGET). This change in D_TARGET changes the inductance of the sensor (Δ Sensor Inductance ∝ Δ D_TARGET), which is measured by the inductance-to-digital converter. When the force is removed the surface returns to its original unstressed shape.

Figure 1-1 Inductive Touch Components

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