The **M93C66-RBN3G/S** is a specific variant of a serial Microwire EEPROM (Electrically Erasable Programmable Read-Only Memory). It is widely used for non-volatile data storage in consumer electronics, automotive modules, and industrial equipment. --- ## 1. Technical Specifications The part number follows a specific nomenclature that defines its technical characteristics: | Feature | Specification | | :--- | :--- | | **Memory Size** | 4 Kbit (organized as 256 x 16-bit or 512 x 8-bit) | | **Interface** | Microwire (3-wire serial) | | **Supply Voltage (Vcc)** | 1.8V to 5.5V (Low Voltage range) | | **Clock Frequency** | 2 MHz (@ 5V) | | **Write Cycles** | 1,000,000 (1 Million) erase/write cycles | | **Data Retention** | 40 Years | | **Operating Temp** | -40°C to +125°C | --- ## 2. Part Number Breakdown The suffix **RBN3G/S** provides critical information regarding the package and environmental standards: * **M93C66**: Base part number for a 4 Kbit Microwire EEPROM. * **-R**: Indicates a supply voltage range of **1.8V to 5.5V**. * **BN**: Represents the **PDIP8** package (Plastic Dual In-line Package, 8 pins). * **3**: Temperature range (Device tested for **-40 to 125 °C**). * **G**: ECOPACK2 (RoHS compliant, Halogen-free). * **S**: Refers to specific manufacturing process or wafer sort (often indicating high-reliability automotive or industrial testing). --- ## 3. Pin Configuration (PDIP8) | Pin Number | Name | Description | | :--- | :--- | :--- | | 1 | **S** | Chip Select (Active High) | | 2 | **C** | Serial Clock | | 3 | **D** | Serial Data Input | | 4 | **Q** | Serial Data Output | | 5 | **Vss** | Ground | | 6 | **ORG** | Organization Select (x8 or x16) | | 7 | **DU** | Don't Use (Must be left floating or tied to Vss) | | 8 | **Vcc** | Supply Voltage | --- ## 4. Key Electronic Features ### A. The ORG (Organization) Pin One of the most important features of this chip is the **ORG pin**. * If connected to **Vcc**, the memory is organized as **256 words of 16 bits**. * If connected to **Vss** (or left floating), it is organized as **512 bytes of 8 bits**. ### B. Sequential Read The M93C66 supports sequential reading, allowing the master device to read the entire memory contents in a single stream without re-sending addresses. ### C. Write Protection The device includes a specific instruction (WDS - Write Disable) to prevent accidental data corruption during power-up or power-down cycles. ---