低成本集成解决方案使新的NFC无线应用程序

　　低成本集成解决方案使新的NFC无线应用程序

　　近场通信（NFC）技术已开始大举进军移动通信产品，如手机，和许多其他应用，包括智能卡、销售点终端、公共交通支付卡、自动售货机、订票、智能广告海报，和更多。为了满足无线NFC解决方案无处不在所需的成本/价格点，半导体供应商和系统设计组织正在制定更高度集成的解决方案，降低系统成本并简化系统实现。

　　无线通信有多种选择，每个节点之间有不同的数据吞吐量范围和物理距离限制，如图1所示。有些无线标准在某些方面是重叠的，有些将具有相同的范围或数据吞吐量，所以最终应用程序将在决定哪个标准最适合系统中起着重要作用。

　　Figure 1： Many wireless standards are available for designers to use in their system. For very-short range communications， the NFC wireless standard can operate at distances of less than 20 cm， vs. other standards that function over much larger distances. （Image courtesy of the NFC Forum.）

　　NFC is a form of RFID， but it has its own set of standards that govern its interface and operation. Vendors that design products to meet the standards will be able to link their products to and interoperate with any other NFC-enabled products. The NFC standards determine not only the contactless operating environment， but also the data formats and data transfer rates.¹

　　However， before delving into the design of NFC systems， we will review some of the basics of NFC operation. The NFC standard defines a short-range wireless connectivity capability that can carry secure two-way interactions between electronic devices. A simple communications link between two NFC devices is easy to establish and does not require any setup by users. Once established the NFC link allows users to access digital content， perform contactless transactions， and even connect electronic devices by placing devices close to each other.