The **M95040-RMB3TP/G** is a high-performance, low-voltage Serial Peripheral Interface (SPI) EEPROM manufactured by STMicroelectronics. It is commonly used for parameter storage in mobile devices, automotive modules, and industrial controllers. --- ### 1. Technical Specifications Below are the primary electrical and physical characteristics: | Feature | Specification | | :--- | :--- | | **Memory Size** | 4 Kbit (512 x 8 bits) | | **Interface** | SPI (Serial Peripheral Interface) | | **Clock Frequency** | Up to 20 MHz | | **Supply Voltage (Vcc)** | 1.8V to 5.5V | | **Package Type** | UFDFPN8 (Ultra-thin Fine pitch Dual Flat No-lead) | | **Operating Temp** | -40°C to +125°C | | **Endurance** | 4 million write cycles | | **Data Retention** | 200 years | --- ### 2. Pin Configuration (UFDFPN8) The device typically uses an 8-pin layout to manage data flow and power: 1. **S# (Chip Select):** Activates the device when held low. 2. **Q (Serial Data Output):** Used for reading data out of the memory. 3. **W# (Write Control):** Hardware protection for the status register. 4. **Vss:** Ground. 5. **D (Serial Data Input):** Used to transfer data/commands into the device. 6. **C (Serial Clock):** Provides timing for data synchronization. 7. **HOLD#:** Pauses serial communication without resetting the chip. 8. **Vcc:** Supply voltage. --- ### 3. Key Operational Features * **Write Protection:** Includes a "Status Register" that allows the user to software-write-protect specific blocks (quarter, half, or whole memory). * **Byte and Page Write:** Supports writing a single byte or a full page (up to 16 bytes) in a single instruction cycle. * **Low Power Consumption:** Features a Deep Power-down mode to conserve energy in battery-operated applications. * **High Reliability:** The `/G` suffix often denotes a "Green" (Halogen-free and RoHS compliant) part with high-reliability automotive or industrial grade qualification. --- ### 4. Part Number Breakdown Understanding the nomenclature helps in identifying specific variants: | Prefix | Memory Type | Density | Voltage | Package | Packing | | :--- | :--- | :--- | :--- | :--- | :--- | | **M95** | SPI EEPROM | **040** (4Kb) | **-R** (1.8V-5.5V) | **MB** (UFDFPN8) | **TP/G** (Tape & Reel/Green) | --- ### 5. Application Code Example (Pseudo-SPI) To communicate with the M95040, a microcontroller typically sends an 8-bit instruction followed by the address and data. ```cpp // Example: Basic Write Enable Command (WREN) void EEPROM_WriteEnable() { DigitalWrite(CS_PIN, LOW); // Select Chip SPI_Transfer(0x06); // WREN Instruction DigitalWrite(CS_PIN, HIGH); // Deselect to trigger internal latch } ```