The **M93C46-RBN3P** is a specific variant of the 1-Kbit serial MICROWIRE EEPROM (Electrically Erasable Programmable Read-Only Memory) manufactured by STMicroelectronics. --- ### ## Technical Specifications Overview This component is commonly used for storing configuration data, calibration constants, or device IDs that must be preserved even when power is removed. | Parameter | Value / Description | | :--- | :--- | | **Memory Size** | 1 Kbit (1,024 bits) | | **Organization** | Configurable: 64 x 16-bit or 128 x 8-bit | | **Interface** | MICROWIRE (3-wire serial interface) | | **Operating Voltage ($V_{CC}$)** | 1.8V to 5.5V | | **Clock Frequency** | 2 MHz (at 4.5V - 5.5V) | | **Package Type** | PDIP8 (Plastic Dual In-line Package, 8 pins) | | **Temperature Range** | -40°C to +85°C (Industrial Grade) | | **Write Cycles** | 1,000,000 cycles | | **Data Retention** | 40 Years | --- ### ## Pin Configuration The M93C46 uses a standard 8-pin layout for serial communication. | Pin Number | Name | Function | | :--- | :--- | :--- | | **1** | **S (CS)** | Chip Select: Activates the device. | | **2** | **C (SK)** | Serial Clock: Synchronizes data transfer. | | **3** | **D (DI)** | Serial Data Input: Receives instructions and data. | | **4** | **Q (DO)** | Serial Data Output: Transfers data out of the device. | | **5** | **$V_{SS}$** | Ground (0V). | | **6** | **ORG** | Organization Select: High = x16 mode, Low/GND = x8 mode. | | **7** | **DU** | Don't Use: Must be left floating or tied to $V_{SS}$. | | **8** | **$V_{CC}$** | Supply Voltage. | --- ### ## Part Number Breakdown: `M93C46-RBN3P` Understanding the suffix is critical for procurement and PCB design: * **M93C46**: Base part number (1 Kbit Microwire EEPROM). * **-R**: Indicates low voltage operation (1.8V to 5.5V). * **BN**: Package type (PDIP8). * **3**: Temperature range (-40°C to +85°C). * **P**: Lead-free and RoHS compliant. --- ### ## Key Features & Behavior 1. **Self-Timed Write Cycle**: The chip manages the internal erase/write timing, typically completed within 5ms. 2. **Ready/Busy Status**: While a write cycle is in progress, the Data Output (Q) pin can be polled to check the status. 3. **Sequential Read**: Allows the user to read the entire memory contents by continuing to toggle the clock after a single read command. 4. **Write Protection**: Includes a "Write Disable" (WDS) instruction to protect data from accidental corruption during power-up or noise interference. --- ### ## Typical Application Circuit ```c // Basic Connection to Microcontroller MCU Pin (GPIO Out) ---> S (Chip Select) MCU Pin (SCK) ---> C (Serial Clock) MCU Pin (MOSI) ---> D (Data In) MCU Pin (MISO) <--- Q (Data Out) 3.3V / 5V ---> VCC GND ---> VSS & ORG (for x8 mode) ```