1 Introduction

Capacitive touch sensing is a unique human-machine interface technology that enables the creation of differentiated user interfaces that can bring value to a wide variety of products. With capacitive sensing, mechanical switches and knobs can be replaced with elegant buttons, sliders, and scroll wheels that integrate seamlessly into the enclosure of a product to simultaneously improve the aesthetics and functionality of the product.

These aesthetic and functional improvements come with a different set of challenges for product designers. For example, capacitive touch requires more attention to detail in the PCB design than a simple mechanical switch does. It also requires more firmware to determine the state of the user interface. Factors such as these can make capacitive touch seem like a challenging technology to develop with. However, the reality is that capacitive touch is not extremely challenging—it is just new and different.

Like many other technologies, the challenges and risks associated with getting a capacitive touch design concept through development and into production can be reduced by having a proven development flow in place. If you are a designer who is new to capacitive touch, or an experienced designer that is new to TI's CapTIvate technology for capacitive sensing, this document provides a step-by-step design flow to go from first concept to mass production. In addition, this document provides checklists at specific points in the development flow to reduce the risk of unforseen issues late in the development cycle.