強(qiáng)大的觸摸感應(yīng)設(shè)計(jì)技術(shù)

　　電容式觸摸傳感器工作在嘈雜的，具有挑戰(zhàn)性的環(huán)境。小心注意的硬件和軟件設(shè)計(jì)技術(shù)可顯著提高設(shè)計(jì)可靠性。

　　本文的目的是描述在嘈雜環(huán)境中開發(fā)電容觸摸應(yīng)用程序時(shí)的最佳設(shè)計(jì)實(shí)踐。它首先將定義由噪聲引起的問題，并解釋這種噪聲通常如何影響系統(tǒng)。將提供硬件指南，以幫助最大限度地提高應(yīng)用程序的自然信噪比（SNR）。所述軟件技術(shù)將描述用于過(guò)濾傳感器信號(hào)的一些常用方法，以進(jìn)一步提高信噪比，并根據(jù)電容傳感器的行為作出解碼決定。

　　The hardware design topics covered are：

　　Selecting a sensor size.

　　Determining the sensors‘ separation.

　　Covering material thickness.

　　Using ground planes to your advantage.

　　Designing the sensors’ layout.

　　Selecting an adhesive.

　　Using series resistance on sensors.

　　Choosing VDD to maximize noise immunity.

　　mTouch? sensing solution systems have passed industry test standards in conducted noise， radiated noise， and radiated susceptibility. This article describes the important aspects of capacitive touch design which， when coupled with good PCB techniques， will allow these systems to continue performing in these extreme testing conditions.

　　For information on the basics of capacitive touch sensing and other more advanced topics， visit the Microchip web site.