The **M93C46-RMB3G** is a specific variant of the 93C46 family, which is a widely used **Serial Microwire EEPROM** (Electrically Erasable Programmable Read-Only Memory). It is manufactured by **STMicroelectronics**. --- ## 1. Technical Specifications The part number breaks down into specific technical attributes regarding capacity, voltage, and packaging. | Feature | Specification | | :--- | :--- | | **Memory Size** | 1 Kbit (1,024 bits) | | **Memory Organization** | Configurable as 64 x 16-bit or 128 x 8-bit | | **Interface** | Microwire (3-Wire Serial Interface) | | **Operating Voltage (Vcc)** | 1.8V to 5.5V | | **Clock Frequency** | 2 MHz (at 4.5V - 5.5V) | | **Write Cycles** | More than 1,000,000 cycles | | **Data Retention** | 40 Years | | **Package Type** | UFDFPN8 (Ultra-thin Fine pitch Dual Flat No-lead) | --- ## 2. Key Internal Components & Functions The device is composed of several electronic subsystems that manage data storage and retrieval: ### A. Memory Array The core of the chip is the **Non-volatile Memory Matrix**. Because it is a 1 Kbit chip, it stores 1024 bits of information that remain intact even when power is removed. ### B. Control Logic & Instruction Decoder Since this uses the Microwire protocol, the chip includes logic to decode specific instructions: * **READ:** Read data from memory. * **WRITE:** Write data to memory. * **ERASE:** Set bits to '1'. * **EWEN/EWDS:** Erase/Write Enable and Disable (a safety feature to prevent accidental data corruption). ### C. The "ORG" Pin (Organization Select) A critical feature of the M93C46 is the **Organization** pin. * If connected to **Vcc**, the memory is organized as **64 words of 16 bits**. * If connected to **GND**, the memory is organized as **128 bytes of 8 bits**. --- ## 3. Decoding the Part Number (M93C46-RMB3G) Understanding the suffix is essential for identifying the specific physical and thermal characteristics: * **M93C46**: Base part number (1 Kbit Microwire EEPROM). * **-R**: Indicates the operating voltage range is **1.8V to 5.5V**. * **MB**: Specifies the package type, which is **UFDFPN8** (MLP 2x3mm). * **3**: Indicates the Temperature Grade (Range 3: **-40°C to +125°C**), suitable for automotive or harsh industrial use. * **G**: Indicates **ECOPACK2** (RoHS compliant, Halogen-free/Lead-free). --- ## 4. Typical Application Circuit When integrating this part into a circuit, four main signal lines are required to communicate with a Microcontroller (MCU): ```text MCU Side M93C46-RMB3G Side [ GPIO ] --------> [ S ] (Chip Select) [ SCK ] --------> [ D ] (Serial Clock) [ MOSI ] --------> [ C ] (Serial Data Input) [ MISO ] <-------- [ Q ] (Serial Data Output) ``` ### Common Uses: * **Parameter Storage:** Storing calibration data or user settings in consumer electronics. * **Identification:** Storing MAC addresses or serial numbers. * **Automotive Systems:** Due to the "Grade 3" temperature rating, it is often used in engine sensors or dashboard controllers. ---