The **M95040-RMB3TG/G** is a low-power, serial Peripheral Interface (SPI) EEPROM (Electrically Erasable Programmable Memory) manufactured by STMicroelectronics. It is designed for high-reliability applications, often found in automotive or industrial control systems. --- ## 1. Technical Specifications The following table summarizes the key electrical and physical parameters of the device: | Parameter | Specification | | :--- | :--- | | **Memory Size** | 4 Kbit (512 x 8 bits) | | **Interface** | SPI (Serial Peripheral Interface) | | **Clock Frequency** | Up to 20 MHz | | **Operating Voltage** | 1.8V to 5.5V | | **Package Type** | UFDFPN8 (Ultra-thin Fine pitch Dual Flat No-lead) | | **Temperature Range** | -40°C to +125°C (Grade 3) | | **Endurance** | 4 Million Write Cycles | | **Data Retention** | 200 Years | --- ## 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):** Receives data/instructions. * **Q (Serial Data Output):** Transfers data out of the device. * **C (Serial Clock):** Synchronizes data movement. * **W (Write Protect):** Hardware protection for the status register. * **HOLD:** Pauses serial communication without deselecting the device. * **Vcc/Vss:** Power supply and Ground. --- ## 3. Key Electronic Features ### A. SPI Protocol Modes The M95040-RMB3TG/G supports SPI bus modes 0 and 3. Data is latched on the rising edge of the clock (C) and shifted out on the falling edge. ### B. Block Protection The memory can be write-protected via the Status Register. This allows the user to protect: 1. None of the memory. 2. The upper quarter (1/4). 3. The upper half (1/2). 4. The entire memory array. ### C. Enhanced Reliability The "G" suffix often denotes a **Green** package (Halogen-free and RoHS compliant). The "R" in the part number indicates the specific voltage range (1.8V to 5.5V), making it suitable for battery-operated devices. --- ## 4. Part Number Breakdown | Segment | Meaning | | :--- | :--- | | **M95** | SPI Family EEPROM | | **040** | 4 Kbit Density | | **-R** | 1.8V to 5.5V Operating Voltage | | **MB** | UFDFPN8 Package | | **3** | Temperature Range (-40°C to +125°C) | | **TG** | Tape and Reel Packing / Green |