Description

This application note covers the fundamentals of Touch-on-Metal (ToM) technology using an LDC1612 Inductance-to-Digital Converter (LDC) and provides guidance for constructing ToM buttons. Simple on and off buttons can be easily implemented using inductive sensing. Additionally, by using a high resolution LDC, microscopic movements in a flat metal button can be sensed and processed to determine how hard a given button was pressed. This approach allows reuse of existing metal surfaces commonly found in many applications such as consumer electronics and appliances.

This report contains a design example for a multi-button brushed aluminum panel and provides guidance on the mechanical system and sensor design, as well as measured performance results of the complete system.