The **M95640-RMB3T/B** is a high-performance, 64-Kbit serial SPI (Serial Peripheral Interface) EEPROM (Electrically Erasable Programmable Memory) manufactured by STMicroelectronics. It is designed for low-voltage, high-reliability applications. ### 1. Technical Specifications Below are the primary electrical and physical characteristics of the component: | Feature | Specification | | :--- | :--- | | **Memory Size** | 64 Kbit (8,192 bytes) | | **Interface** | SPI (Mode 0 and Mode 3) | | **Max Clock Frequency** | 20 MHz (at 4.5V - 5.5V) / 5 MHz (at 1.8V) | | **Operating Voltage ($V_{CC}$)** | 1.8V to 5.5V | | **Package Type** | UFDFPN8 (Ultra-thin Fine pitch Dual Flat No-lead) | | **Write Cycle Time** | Max 5 ms | | **Data Retention** | 40 Years | | **Endurance** | 4,000,000 Write Cycles | --- ### 2. Functional Pins The UFDFPN8 package typically utilizes the following pinout configuration: 1. **S# (Chip Select):** Activates the device when pulled low. 2. **Q (Serial Data Output):** Used to read data out of the memory. 3. **W# (Write Protect):** Hardware protection to prevent write operations to the status register. 4. **$V_{SS}$:** Ground. 5. **D (Serial Data Input):** Used to send instructions, addresses, and data to the chip. 6. **C (Serial Clock):** Synchronizes the data transfer. 7. **HOLD#:** Pauses serial communication without deselecting the device. 8. **$V_{CC}$:** Supply voltage. --- ### 3. Key Features & Protection * **Byte and Page Write:** Supports writing a single byte or a full page (up to 32 bytes) in one cycle. * **Block Protection:** Internal software circuitry allows the user to protect quarters, halves, or the entire memory array via the Status Register. * **Identification Page:** Includes an additional 32-byte page used to store sensitive application parameters (can be permanently locked in Read-Only mode). * **ESD Protection:** High resistance to Electrostatic Discharge (up to 4000V Human Body Model). --- ### 4. Part Number Breakdown: `M95640-RMB3T/B` * **M95:** SPI Family EEPROM. * **640:** 64 Kbit density. * **-R:** Operating voltage range of 1.8V to 5.5V. * **MB:** Package code for UFDFPN8 ($2 \times 3$ mm). * **3:** Range 3 temperature ($–40$ to $+125$ °C). * **T:** Tape and Reel packaging. * **/B:** Process technology/generation identifier.