### M93C46-RBN7: Technical Overview The **M93C46-RBN7** is a 1-Kbit low-voltage serial EEPROM (Electrically Erasable Programmable Memory) manufactured by STMicroelectronics. It is commonly used for storing small amounts of configuration data, calibration parameters, or device IDs that must be preserved when power is lost. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Memory Size** | 1 Kbit (1,024 bits) | | **Organization** | Configurable: 64 x 16-bit or 128 x 8-bit | | **Interface** | MICROWIRE (Serial 3-Wire) | | **Operating Voltage** | 1.8V to 5.5V | | **Clock Frequency** | 2 MHz (at 4.5V) / 1 MHz (at 1.8V) | | **Write Cycles** | 1,000,000+ cycles | | **Data Retention** | 40 Years | | **Package Type** | TSSOP8 or SO8 (The "N" usually denotes specific packaging) | | **Temperature Range** | -40°C to +85°C (Industrial Grade) | --- ### 2. Pin Configuration and Functions The M93C46 typically uses an 8-pin layout. The most critical pins are: * **S (Chip Select):** Activates the device when high. * **D (Serial Data Input):** Receives instructions and data. * **Q (Serial Data Output):** Sends data back to the microcontroller. * **C (Serial Clock):** Synchronizes the data transfer. * **ORG (Organization):** When tied to Vcc, the memory is organized as $64 \times 16$. When tied to GND, it is $128 \times 8$. --- ### 3. Part Number Breakdown (Suffix Meaning) Understanding the `RBN7` suffix is crucial for sourcing replacements: * **M93C46:** Device Family (1K MICROWIRE EEPROM). * **-R:** Operating Voltage range (1.8V to 5.5V). * **B:** Indicates a specific die revision or process technology. * **N:** Package code (usually indicates PDIP or a specific plastic small-outline package). * **7:** Temperature range code (Industrial, -40°C to +85°C, with specific testing/qualification). --- ### 4. Typical Application Circuit The device communicates with a Microcontroller (MCU) using the MICROWIRE protocol, which is similar to SPI but uses a specific start-bit sequence. ```c // Example logic for reading a 16-bit word (C code snippet) void Read_EEPROM(uint8_t address) { Set_CS_High(); Send_Start_Bit(1); Send_OpCode(READ); // 10 Send_Address(address); uint16_t data = Receive_16Bits(); Set_CS_Low(); } ``` --- ### 5. Notable Features * **Sequential Read:** Allows reading the entire memory contents by continuing to provide clock pulses after the first word is read. * **Write Protection:** Includes a "Write Disable" mode to prevent accidental data corruption during power-up or power-down. * **Ready/Busy Status:** The Data Out (Q) pin can be polled after a write instruction to see if the internal write cycle is complete.