Latest capacitive touch screen assemblies address EMC issues

Latest from AndersDX comes news of a portfolio of technologies designed to address EMC issues with capacitive touch screen assemblies. The technologies are backed by design-in support delivered by its display specialists, and are available for a complete touch screen assembly. EMI coupling for capacitive touch screens is a growing problem. The performance of the touch screen assembly can be severely affected by external noise and emissions from the host product itself in addition to the display and associated electronics which may also emit EMI. AndersDX touch screen experts, Mike Logan, display and input technology manager, and Paul Hooper, European sales manager, have worked with key suppliers to research and implement technologies that address interference of capacitive touch screens. The use of specifically customised driver ICs that have unique features and EMI specific filter circuits in addition to other measures, all ensure that each assembly can work reliably in its target environment without adding a significant cost burden. These techniques will need to be applied on a case by case basis taking into account multiple factors and in particular the environment and the design of the host product, says the company. Commenting, Mike Logan, said: “There is no one-size-fits-all solution here. Engineers understand that EMC needs to be tackled from the ground up. Capacitive touch screens are sensitive to EMI and protection can’t be added as an afterthought. It is essential that customers approach us before they start their assembly design. We will work with them from initial concept right through to qualification, to ensure that the display works reliably in their application, doesn’t interfere with other systems in the environment and complies with the required standards. Customers need to involve us from the start, though, it really isn’t possible to ‘patch’ a problem design.”