The **M95640-RMB3G** is a high-performance, electrically erasable programmable read-only memory (EEPROM) manufactured by **STMicroelectronics**. It is part of the M95 series, commonly used in automotive and industrial applications due to its reliability and low power consumption. --- ## 1. Technical Specifications The following table summarizes the key electrical and physical parameters of the M95640-RMB3G: | Parameter | Specification | | :--- | :--- | | **Memory Size** | 64 Kbit (8,192 x 8 bits) | | **Interface** | SPI (Serial Peripheral Interface) | | **Clock Frequency** | Up to 20 MHz | | **Operating Voltage ($V_{CC}$)** | 1.8V to 5.5V | | **Package Type** | UFDFPN8 (MLP8) - Ultra-thin Fine pitch Dual Flat No-lead | | **Temperature Range** | -40°C to +125°C (Grade 3) | | **Data Retention** | 40 Years | | **Write Cycles** | 4,000,000 Cycles | --- ## 2. Pin Configuration The device typically uses an 8-pin layout. Below is the functional description of the pins: * **S (Chip Select):** Activates the device when pulled low. * **D (Serial Data Input):** Used to transfer data into the device. * **Q (Serial Data Output):** Used to transfer data out of the device. * **C (Serial Clock):** Provides the timing for the serial interface. * **W (Write Protect):** Hardware protection to prevent write operations. * **HOLD (Hold):** Pauses serial communication without deselecting the device. * **$V_{CC}$ / $V_{SS}$:** Power supply and Ground. --- ## 3. Key Features ### A. SPI Protocol Modes The device supports SPI modes **(0,0)** and **(1,1)**, ensuring compatibility with most microcontrollers. Data is latched on the rising edge of the clock (C) and shifted out on the falling edge. ### B. Enhanced Data Protection 1. **Status Register:** Includes a "Write Enable Latch" bit and "Block Protect" bits. 2. **Hardware Protection:** The $\bar{W}$ pin can be used to freeze the status register, preventing accidental overwrites. 3. **Software Protection:** Users can configure specific quarters or halves of the memory array as read-only. ### C. Write Operations The chip supports **Byte Write** and **Page Write** (up to 32 bytes). It features a self-timed write cycle that typically completes in under 5ms. --- ## 4. Part Number Breakdown: `M95640-RMB3G` The suffix provides specific details about the variant: * **M95:** SPI Family EEPROM. * **640:** 64 Kbit density. * **-R:** Operating voltage range (1.8V to 5.5V). * **MB:** UFDFPN8 package (2x3 mm). * **3:** Temperature range (-40 to 125 °C). * **G:** ECOPACK2 (RoHS compliant and Halogen-free).