Capacitive switch technology

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By Steve Baker | Jan 13, 2016
Capacitive switch technology

When evaluating capacitive switch technology, it is important to consider the different design options available.  At GM Nameplate, we offer capacitive switch technologies that take advantage of both self and mutual capacitive touch sensor designs. Each sensor design approach has unique advantages depending on the intended application and target industry.

Self capacitive touch sensors require a single pin on the touch controller, which is linked to a single touch sensitive location on your product. This type of design is well suited for backlit touch switches with large lit regions, which is a very popular design option today. These sensors often allow for simplified circuit layouts, which can also help reduce manufacturing costs.  In many cases, they also require less space for circuit routing, which is an important factor for space limited designs.

When compared to mutual capacitive designs, self capacitive designs can be less effective when used in environments where standing moisture is present.  They can also be more difficult to tune for sensitive touch applications.

Mutual capacitive touch sensors are linked to two pins on the touch controller.  This can allow for matrixing of touch sensors to reduce the overall pin count on designs with a large number of touch sensitive zones.  Sensors with mutual capacitive design structures can be easier to tune for optimal performance on a variety of touch surface thicknesses and in some cases they may provide reduced signal noise for products in operating environments with EMI noise sources. 

When compared to self capacitive switches, mutual capacitive designs are also better suited to handle moist environments or applications requiring gloved hands.

Click here to learn more about the evolution of tactile feedback technology in user interface devices.