## Detailed Technical Analysis: M24LR64-R-MB6T/2 The **M24LR64-R-MB6T/2** is a dynamic NFC/RFID tag IC developed by STMicroelectronics. It is unique because it features a **dual-interface**: it can be accessed via a wired I2C interface or a wireless ISO 15693 (13.56 MHz) interface. --- ### 1. Key Specifications The following table highlights the primary electrical and functional characteristics of the component: | Parameter | Specification | | :--- | :--- | | **Memory Size** | 64 Kbits (8192 bytes) | | **Memory Type** | EEPROM | | **Interfaces** | I2C (wired) and ISO 15693 / NFC Forum Type 5 (wireless) | | **I2C Clock Frequency** | Up to 400 kHz | | **Carrier Frequency** | 13.56 MHz | | **Operating Voltage (Vcc)** | 1.8V to 5.5V | | **Package Type** | UFDFPN8 (2x3 mm) or TSSOP8 | | **Data Retention** | 40 years | | **Write Cycles** | 1,000,000 cycles | --- ### 2. Functional Components The IC is divided into several specialized sub-sections that allow it to act as a bridge between an embedded system and an NFC reader (like a smartphone). #### A. The EEPROM Memory Bank The 64 Kbit memory is organized as 2048 blocks of 32 bits each. It is non-volatile, meaning data is retained even when power is removed. #### B. The Dual Interface 1. **I2C Interface:** Allows a local microcontroller (MCU) to read or update configuration settings and data. 2. **RF Interface:** Allows an external NFC-enabled device to read/write data wirelessly. The device is powered by the energy harvested from the RF field of the reader. #### C. Energy Harvesting (V_out) One of the most powerful features of this part is the **Energy Harvesting** mode. When placed in an induction field, it can output excess energy via an analog pin to power other low-power components (like a low-power MCU or a sensor). --- ### 3. Pinout Configuration *Typical for the UFDFPN8/TSSOP8 package:* | Pin | Name | Description | | :--- | :--- | :--- | | 1 | **AC0** | Antenna Connection 0 | | 2 | **AC1** | Antenna Connection 1 | | 3 | **V_out** | Energy Harvesting Output | | 4 | **Vss** | Ground | | 5 | **SDA** | I2C Serial Data | | 6 | **SCL** | I2C Serial Clock | | 7 | **WIP/BUSY** | Write in Progress / RF Busy Output | | 8 | **Vcc** | Power Supply | --- ### 4. Use Case Example: I2C Initialization Below is a conceptual example of how an MCU might interface with the M24LR64 via I2C using C-style logic: ```c // Example I2C Address for M24LR64 (User memory) #define M24LR64_ADDR 0x53 void write_nfc_data(uint16_t mem_address, uint8_t data) { I2C_Start(); I2C_Send_Address(M24LR64_ADDR << 1 | WRITE_BIT); I2C_Send_Byte((uint8_t)(mem_address >> 8)); // MSB I2C_Send_Byte((uint8_t)(mem_address & 0xFF)); // LSB I2C_Send_Byte(data); I2C_Stop(); } ``` --- ### 5. Common Applications * **Asset Tracking:** Storing maintenance logs that can be updated via a phone without powering the main device. * **Parameter Setting:** Configuring a sealed industrial device (waterproof) via NFC. * **Medical Devices:** Storing patient data on wearable sensors. * **Electronic Shelf Labels (ESL):** Updating prices wirelessly.