The **M93C46-RMB7** is a 1-Kbit low-voltage serial Microwire EEPROM (Electrically Erasable Programmable Memory) manufactured by STMicroelectronics. It is commonly used for storing configuration data, user settings, and calibration parameters in embedded systems. --- ## 1. Technical Specifications Below are the primary electronic characteristics of the M93C46-RMB7: | Parameter | Specification | | :--- | :--- | | **Memory Size** | 1 Kbit (1,024 bits) | | **Organization** | User-selectable: 64 x 16-bit or 128 x 8-bit | | **Interface** | Microwire (3-wire or 4-wire serial) | | **Supply Voltage ($V_{CC}$)** | 1.8V to 5.5V | | **Clock Frequency ($f_C$)** | 2 MHz (at 4.5V) / 1 MHz (at 1.8V) | | **Package Type** | UFDFPN8 (MLP8) - Ultra-thin Fine Pitch Dual Flat No-lead | | **Temperature Range** | -40°C to +85°C (Industrial Grade) | | **Endurance** | 4 million write cycles | | **Data Retention** | 200 years | --- ## 2. Pinout Configuration The device usually comes in an 8-pin package. Here is the standard pin description: 1. **S (Chip Select):** Activates the device when pulled High. 2. **C (Serial Clock):** Synchronizes data transfer. 3. **D (Serial Data Input):** Receives instructions and data. 4. **Q (Serial Data Output):** Outputs data during read operations. 5. **$V_{SS}$:** Ground. 6. **ORG (Organization):** Determines memory structure (High = x16, Low/Floating = x8). 7. **DU (Don't Use):** Usually left unconnected. 8. **$V_{CC}$:** Power supply. --- ## 3. Key Electronic Features ### A. Low Voltage Operation The "**-R**" in the part number indicates the low-voltage range (1.8V to 5.5V). This makes it ideal for battery-powered devices like remote controls or wearable sensors. ### B. Microwire Protocol Unlike I2C (which uses addressing) or SPI (which uses standard 8-bit chunks), Microwire is a simpler synchronous protocol. It relies on a "Start Bit" followed by an Op-code (Read, Write, Erase). ### C. Write Protection The device features a **Write Disable (WDS)** instruction that prevents accidental data corruption during power-up or power-down cycles. A **Write Enable (WEN)** command must be sent before any modification is allowed. ### D. Automatic Write Cycle When a write command is issued, the chip handles the erasing and programming internally. The **Ready/Busy** status can be monitored via the Data Output (Q) pin to check when the write cycle is complete. --- ## 4. Part Number Breakdown: M93C46-RMB7 * **M93C46:** 1-Kbit Microwire EEPROM family. * **-R:** Operating voltage range of 1.8V to 5.5V. * **MB:** Package type (UFDFPN8 / MLP8). * **7:** Device grade (Industrial temperature range -40°C to 85°C, Lead-free, Halogen-free).