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TA1147

Switches and buttons for automotive application have design constraints not even imagined by non-automotive engineers. They also have to be cost-effective, ruling out hermetically sealed switches. Converting to capacitive touch switches provides an implementation with no mechanical parts, the ability to conform to surfaces, and flexible backlighting. Potential applications include: touch switches on top of gauges, touch sense door entry, windshield touch switches, and other dashboard applications. This article will address key topics such as the physics behind touch sense capacitance and how to measure capacitance, the use of IO Analog Multiplexers (IAM) and how every pin can be a capacitive input, and how to implement capacitive touch sensors in automotive designs, among others. With no mechanical parts and easily conforming to curved surfaces, touch sense capacitor switches can be an ideal technology for today’s automotive applications

• 225.74 KB
• 2012/08/03