The **M95640-RDL5T** is a specific variant of the M95640 family of Electrically Erasable Programmable Read-Only Memory (EEPROM) chips manufactured by **STMicroelectronics**. It is commonly used in automotive and industrial applications for non-volatile data storage. --- ### 1. Key Technical Specifications The following table outlines the primary electrical and physical characteristics of this component: | Feature | Specification | | :--- | :--- | | **Memory Size** | 64 Kbit (8,192 x 8 bits) | | **Interface** | SPI (Serial Peripheral Interface) | | **Operating Voltage** | 1.8V to 5.5V | | **Clock Frequency** | Up to 20 MHz (at 4.5V - 5.5V) | | **Package Type** | MLP (UFDFPN8) / DFN8 | | **Temperature Range** | -40°C to +85°C | | **Endurance** | 4 Million Write Cycles | | **Data Retention** | 200 Years | --- ### 2. Functional Description The M95640-RDL5T operates as a slave device on the SPI bus. It uses a high-speed synchronous protocol consisting of four main signals: * **S (Chip Select):** Activates the device. * **D (Serial Data Input):** Receives instructions, addresses, and data. * **Q (Serial Data Output):** Sends data to the SPI master. * **C (Serial Clock):** Synchronizes data movement. #### Pin Configuration (Standard 8-pin Layout) 1. **S#**: Chip Select 2. **Q**: Serial Data Output 3. **W#**: Write Protect 4. **VSS**: Ground 5. **D**: Serial Data Input 6. **C**: Serial Clock 7. **HOLD#**: Pause Serial Communication 8. **VCC**: Supply Voltage --- ### 3. Decoding the Part Number The suffix **"RDL5T"** provides specific information regarding the hardware revision and packaging: * **M95640:** Base Part Number (64 Kbit SPI EEPROM). * **-R:** Operating Voltage Range (1.8V to 5.5V). * **DL:** Package Code (likely referring to the UFDFPN8 thin dual flat no-lead package). * **5:** Temperature range (-40°C to +85°C). * **T:** Tape and Reel packing. --- ### 4. Typical Application Circuit When integrating this part into a PCB design, decoupling capacitors are essential for stability. ```cpp // Example: Arduino/C++ SPI Write Protection Register Logic // This logic demonstrates how a microcontroller interacts with the M95640 #define CS_PIN 10 void setup() { pinMode(CS_PIN, OUTPUT); digitalWrite(CS_PIN, HIGH); // Disable chip initially SPI.begin(); } void writeEnable() { digitalWrite(CS_PIN, LOW); SPI.transfer(0x06); // WREN Instruction (0000 0110) digitalWrite(CS_PIN, HIGH); } ``` ---