原标题：ST M24LR04E-R NFC-RFID标签解决方案

　　ST公司的M24LR04E-R是集成了双路接口的电擦除可编存储器(EEPROM),包括I2C模式的512x8b和RF模式的128x32b RF,同时具有能量采集的模拟输出,以及用户可编程的数字输出和密码保护,主要用作NFC/RFID标签.本文介绍M24LR04E-R主要特性,电路框图, M24LR-DISCOVERY评估板和RF收发器演示板主要特性,电路图,材料清单和PCB元件布局图.

　　The M24LR04E-R device is a Dynamic NFC/RFID tag IC with a dual-interface, electrically erasable programmable memory (EEPROM). It features an I2C interface and can be operated from a VCCpower supply. It is also a contactless memory powered by the received carrier electromagnetic wave. The M24LR04E-R is organized as 512 × 8 bits in the I2C mode and as 128 × 32 bits in RF mode.

　　The M24LR04E-R also features an energy harvesting analog output, as well as a user-configurable digital output pin toggling during either RF write in progress or RF busy mode.I2C uses a two-wire serial interface, comprising a bidirectional data line and a clock line. The devices carry a built-in 4-bit device type identifier code (1010) in accordance with the I2C bus definition.

　　The device behaves as a slave in the I2C protocol, with all memory operations synchronized by the serial clock. Read and Write operations are initiated by a Start condition, generated by the bus master. The Start condition is followed by a device select code and Read/Write bit (RW), terminated by an acknowledge bit.

　　When writing data to the memory, the device inserts an acknowledge bit during the 9th bit time, following the bus master’s 8-bit transmission. When data is read by the bus master, the bus master acknowledges the receipt of the data byte in the same way. Data transfers are terminated by a Stop condition after an Ack for Write, and after a NoAck for Read.In the ISO15693/ISO18000-3 mode 1 RF mode, the M24LR04E-R is accessed via the 13.56 MHz carrier electromagnetic wave on which incoming data are demodulated from the received signal amplitude modulation (ASK: amplitude shift keying). When connected to an antenna, the operating power is derived from the RF energy and no external power supply is required. The received ASK wave is 10% or 100% modulated with a data rate of 1.6 Kbit/s using the 1/256 pulse coding mode or a data rate of 26 Kbit/s using the 1/4 pulse coding mode.

　　Outgoing data are generated by the M24LR04E-R load variation using Manchester coding with one or two subcarrier frequencies at 423 kHz and 484 kHz. Data are transferred from the M24LR04E-R at 6.6 Kbit/s in low data rate mode and 26 Kbit/s high data rate mode. The M24LR04E-R supports the 53 Kbit/s fast mode in high data rate mode using one subcarrier frequency at 423 kHz.

　　The M24LR04E-R follows the ISO 15693 and ISO 18000-3 mode 1 recommendation for radio-frequency power and signal interface.

　　The M24LR04E-R provides an Energy harvesting mode on the analog output pin Vout. When the Energy harvesting mode is activated, the M24LR04E-R can output the excess energy coming from the RF field on the Vout analog pin. In case the RF field strength is insufficient or when Energy harvesting mode is disabled, the analog output pin Vout goes into high-Z state and Energy harvesting mode is automatically stopped.

　　The M24LR04E-R features a user configurable digital out pin RF WIP/BUSY that can be used to drive a micro controller interrupt input pin (available only when the M24LR04E-R is correctly powered on the Vcc pin).

　　When configured in the RF write in progress mode (RF WIP mode), the RF WIP/BUSY pin is driven low for the entire duration of the RF internal write operation. When configured in the RF busy mode (RF BUSY mode), the RF WIP/BUSY pin is driven low for the entire duration of the RF command progress.

　　The RF WIP/BUSY pin is an open drain output and must be connected to a pull-up resistor.

　　M24LR04E-R主要特性:

　　I2C interface

　　Two-wire I2C serial interface supports 400 kHz protocol

　　Single supply voltage:

　　1.8 V to 5.5 V

　　Byte and Page Write (up to 4 bytes)

　　Random and Sequential read modes

　　Self-timed programming cycle

　　Automatic address incrementing

　　Enhanced ESD/latch-up protection

　　I²C timeout

　　Contactless interface

　　ISO 15693 and ISO 18000-3 mode 1 compatible

　　13.56 MHz ±7k Hz carrier frequency

　　To tag: 10% or 100% ASK modulation using 1/4 (26 Kbit/s) or 1/256 (1.6 Kbit/s) pulse position coding

　　From tag: load modulation using Manchester coding with 423 kHz and 484 kHz subcarriers in low (6.6 kbit/s) or high (26 kbit/s) data rate mode. Supports the 53 kbit/s data rate with Fast commands

　　Internal tuning capacitance: 27.5pF

　　64-bit unique identifier (UID)

　　Read Block & Write (32-bit blocks)

　　Digital output pin

　　User configurable pin: RF write in progress or RF busy mode

　　Energy harvesting

　　Analog pin for energy harvesting

　　4 sink current configurable ranges

　　Memory

　　4-Kbit EEPROM organized into:

　　512 bytes in I2C mode

　　128 blocks of 32 bits in RF mode

　　Write time

　　I2C: 5 ms (max.)

　　RF: 5.75 ms including the internal Verify time

　　More than 1 million write cycles

　　More than 40-year data retention

　　Multiple password protection in RF mode

　　Single password protection in I2C mode

　　Package

　　ECOPACK2®(RoHS compliant and Halogen-free)

　　图1. M24LR04E-R电路框图

　　M24LR-DISCOVERY评估板

　　The M24LR-DISCOVERY kit helps you evaluate the M24LRXX-E Dual Interface EEPROM that features an energy harvesting analog output, as well as a user-configurable digital output.

　　The M24LR-DISCOVERY kit is delivered with a battery-less M24LR board that can be powered by RFID readers or NFC phones supporting the ISO/IEC15693 protocol. It is based on an M24LR04E-R I²C -ISO/IEC15693 Dual Interface EEPROM, an 8-bit STM8L152C6T6 ultralow power microcontroller, and includes an STTS751 temperature sensor, a 24-segment LCD, and 2 push buttons.

　　The M24LR-DISCOVERY kit also comes with an USB RF transceiver demonstration board that includes the CR95HF 13.56-MHz multi-protocol contactless transceiver. It is based on a 32-bit, STM32F103CBT6 performance line microcontroller and is connected to a computer host via its USB connector.

　　图2. M24LR-DISCOVERY评估板外形图

　　图3.RF收发器演示板外形图

　　M24LR-DISCOVERY评估板主要特性:

　　The M24LR-DISCOVERY kit includes M24LR board and the RF transceiver board which offer the following features.

　　M24LR board

　　• M24LR04E-R, a 4-Kbit EEPROM with an I²C-ISO/IEC 15693 dual interface and an energy harvesting analog output (Vout pin) and a user-configurable digital output (RF Write-in-progress or Busy pin) in an SO8N package

　　• 9-turn, 13.56-MHz etched antenna (20mm x 40mm) for RF powering and communication

　　• STM8L152C6T6, 8-bit ultralow power microcontroller with up to 32 Kbytes of Flash memory, 2 Kbytes of RAM, and 1 Kbyte of Data EEPROM in a 48-pin LQFP package

　　• STTS751 I²C low power temperature sensor

　　• 28-pin LCD on DIP24 socket (24 segments, 4 commons)

　　• Two push buttons (User and Reset)

　　• HC-49S-C20SSA, a 4-MHz crystal oscillator (not used in demonstration firmware)

　　• 4-pin connector (CN1) for STM8L programming and debug (SWIM)

　　• 2-pin connector (CN2) for external power supply source (3 to 6V)

　　• 5-pin connector (CN3) for M24LR04E-R and I²C bus probing

　　• 3-pin switch (JP1) to select M24LR board power source (M24LR04E Vout pin or external)

　　RF transceiver board

　　• CR95HF, a 13.56-MHz multi-protocol contactless transceiver IC with SPI and UART serial access communication

　　• 2-turn, 13.56-MHz etched loop antenna (47mm x 34 mm) with associated tuning circuit and lowpass filter

　　• STM32F103CBT6, a 32-bit microcontroller with 128 Kbytes of Flash memory and USB interface in a 48-pin LQFP package

　　• KF33BDT, a 3.3V low dropout (LDO) voltage regulator

　　• USB connector

　　• NX2520SA, a 27.12-MHz EXS00A-CS01206 crystal oscillator for CR95HF transceiver

　　• HC-49XA-C20QQA-8.000MHz for STM32

　　• 20-pin JTAG connector for STM32 programming and debugging

　　• 1 push button (Reset)

　　图4.M24LR-DISCOVERY评估板电路图

　　图5.RF收发器演示板电路图(STM32连接)

　　图6.RF收发器演示板电路图(CR95HF连接)

　　M24LR-DISCOVERY评估板材料清单: