## M93C46-RDS3 Technical Overview The **M93C46-RDS3** is a 1-Kbit low-voltage serial EEPROM (Electrically Erasable Programmable Memory) manufactured by STMicroelectronics. It is commonly used in applications requiring non-volatile storage for configuration data, calibration parameters, or device IDs. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Memory Size** | 1 Kbit (1,024 bits) | | **Organization** | 64 x 16 bits or 128 x 8 bits (Selectable via ORG pin) | | **Interface** | MICROWIRE (3-wire serial interface) | | **Operating Voltage** | 1.8V to 5.5V | | **Clock Frequency** | Up to 2 MHz | | **Package Type** | TSSOP8 (indicated by the "RDS" suffix) | | **Temperature Range** | -40°C to +125°C (Grade 3) | | **Endurance** | 4 million write cycles | | **Data Retention** | 200 years | --- ### 2. Pin Configuration (TSSOP8) The device typically follows a standard 8-pin layout for MICROWIRE EEPROMs: 1. **S (Chip Select):** Enables the device when 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. **Vss:** Ground. 6. **ORG (Organization Select):** Sets the word width (High = 16-bit, Low/NC = 8-bit). 7. **DU (Don't Use):** Usually left unconnected or grounded. 8. **Vcc:** Supply voltage. --- ### 3. Part Number Breakdown Understanding the suffix **RDS3** is crucial for identifying the specific variant: * **M93C46:** The base family (1-Kbit MICROWIRE EEPROM). * **-R:** Indicates the operating voltage range is **1.8V to 5.5V**. * **DS:** Refers to the **TSSOP8** package (8-lead Thin Shrink Small Outline Package, 3mm width). * **3:** Indicates **Automotive Grade 3** temperature range (-40°C to +125°C). --- ### 4. Functional Features * **Self-Timed Programming:** The device handles the internal write cycle timing automatically once a write command is received. * **Ready/Busy Signal:** During a write cycle, the Data Output (Q) pin can be polled to check if the device is busy or ready for the next instruction. * **Sequential Read:** It supports reading the entire memory contents in a single continuous stream. * **Write Protection:** Includes instructions to enable or disable write operations (WEN/WDS) to prevent accidental data corruption. --- ### 5. Application Circuit Example To interface this with a microcontroller, use the following logic: ```c // Pseudo-code for a Read Operation 1. Set CS (Chip Select) HIGH. 2. Send READ Opcode (110) via DI. 3. Send Address (7 or 6 bits depending on ORG). 4. Read bits from DO on the falling edge of the clock. 5. Set CS LOW to end the cycle. ```