### Overview of the M24LR64-RMB6T/2 The **M24LR64-RMB6T/2** is a unique electronic component manufactured by STMicroelectronics. It is classified as a **Dual Interface EEPROM** (Electrically Erasable Programmable Read-Only Memory). The defining feature of this chip is its ability to be accessed through two distinct interfaces: a wired **I2C interface** and a wireless **RFID/NFC interface**. --- ### Technical Specifications | Parameter | Specification | | :--- | :--- | | **Memory Size** | 64 Kbits (8192 bytes) | | **I2C Interface** | Fast Mode (400 kHz), 1.8V to 5.5V supply | | **RF Interface** | ISO 15693 / ISO 18000-3 Mode 1 | | **Carrier Frequency** | 13.56 MHz (HF) | | **Energy Harvesting** | Analog output providing excess energy from RF field | | **Package** | UFDFPN8 (2 x 3 mm) | | **Data Retention** | 40 Years | | **Endurance** | 1 Million Write cycles | --- ### Core Functional Parts #### 1. The Dual Interface Memory Bank The 64 Kbit memory is shared between both interfaces. This allows a device to receive data via NFC (e.g., from a smartphone) while the local Microcontroller (MCU) reads that same data via I2C once the device is powered on. #### 2. Energy Harvesting (Vout) One of the most powerful features of this chip is the **Energy Harvesting mode**. When the chip is placed in a strong 13.56 MHz electromagnetic field (from an NFC reader), it can convert that RF energy into a DC voltage. * This voltage is delivered through the `Vout` pin. * It can be used to power low-power components like an external MCU or sensors, potentially enabling "battery-less" operation. #### 3. The RF Interface (ISO 15693) Unlike standard NFC tags (which often use ISO 14443), the M24LR series uses **ISO 15693**. * **Vicinity Range:** It allows for a longer read range (up to 1 meter with a powerful reader). * **Antenna:** It requires an external coil antenna connected to the `AC0` and `AC1` pins. #### 4. The I2C Interface This is the standard wired connection for an embedded system. It allows a local processor to configure the chip, read harvested data, or update status information that can later be read via a smartphone. --- ### Pin Configuration (UFDFPN8) | Pin | Name | Description | | :--- | :--- | :--- | | 1 | **AC0** | Antenna Coil Connection | | 2 | **AC1** | Antenna Coil Connection | | 3 | **Vout** | Energy Harvesting Output | | 4 | **Vss** | Ground | | 5 | **SDA** | I2C Serial Data | | 6 | **SCL** | I2C Serial Clock | | 7 | **WIP/BUSY** | Write in Progress or RF Busy Output | | 8 | **Vcc** | Power Supply (for I2C operations) | --- ### Common Applications * **Electronic Shelf Labels (ESL):** Updating prices via NFC. * **Medical Sensors:** Loggers that transmit data to a phone without needing a battery to be charged. * **Industrial Programming:** Configuring a machine's parameters through the packaging via NFC before it is even powered on. * **Smart Home Appliances:** Firmware updates or error diagnostic retrieval.