ST CR95HF多协议无接触天线设计和阻抗匹配解决方案

ST公司的CR95HF是具有SPI和UART串行接入的多协议无接触13.6MHz收发器IC,可作为13.56MHz空中接口的模拟前端(AFE),支持ISO/IEC 14443 A和B, ISO/IEC 15693 (单或双用户)以及ISO/IEC 18092等协议,能管理阅读器模式的帧编码和译码,主要用在NFC, 接近标准应用.本文介绍了CR95HF主要特性,方框图和MCU的典型应用以及DEMO-CR95HF-A 演示板等效电路,天线电路框图,和DEMO-CR95HF-A电路与所用材料.
The CR95HF is an integrated transceiver IC for contactless applications.
The CR95HF manages the frame coding and decoding in Reader mode for standard applications such as NFC, proximity and vicinity standards.
The CR95HF embeds the Analog Front End for 13.56 MHz Air Interface.
The CR95HF supports ISO/IEC 14443 A and B, ISO/IEC 15693 (single or double subcarrier) and ISO/IEC 18092 protocols.
CR95HF主要特性:
■ Operating modes supported:
– Reader/Writer
■ Hardware features
– Dedicated internal frame controller
– Highly integrated Analog Front End (AFE)
for RF communications
– Transmission and reception modes
– Optimized power management
– Tag Detection modes
■ RF communication @13.56 MHz
– ISO/IEC 14443 A and B
ISO/IEC 15693
– ISO/IEC 18092
■ Communication interfaces with a Host Controller
– Serial peripheral interface (SPI) Slave interface
– Universal asynchronous
receiver/transmitter (UART)
■ 32-pin VFQFPN (5 x 5 mm) ECOPACK® package
CR95HF应用:
Typical protocols supported:
■ ISO/IEC 14443-3 Type A and B cards and tags
■ ISO/IEC 15693 and ISO/IEC 18000-3M1 tags
■ NFC forum tag: Types 2, 3 and 4
■ ST Dual Interface EEPROM

图1.CR95HF方框图

图2.CR95HF应用示意图
The goal of this application note is to provide guidelines to design a CR95HF antenna which impedance matches to the CR95HF impedance. This allows to achieve the best RF communications between the CR95HF transceiver integrated circuit (IC) and ISO15693 or ISO14443 RF memory tags.
The DEMO-CR95HF-A is a demonstration board for the ...