The **M95320-RBN3TP** is a specific variant of the 32-Kbit serial SPI (Serial Peripheral Interface) Bus EEPROM manufactured by STMicroelectronics. It is widely used for non-volatile parameter storage in industrial and consumer electronics. --- ## 1. Technical Specifications The part number indicates specific characteristics regarding density, voltage, and packaging. | Feature | Specification | | :--- | :--- | | **Memory Size** | 32 Kbit (4,096 bytes x 8 bits) | | **Interface** | SPI (Mode 0 and Mode 3) | | **Clock Frequency** | Up to 20 MHz | | **Operating Voltage ($V_{CC}$)** | 1.8V to 5.5V | | **Operating Temperature** | -40°C to +125°C (Automotive Grade 3) | | **Write Cycles** | 4 Million cycles (typical) | | **Data Retention** | 200 Years | | **Package** | SOT23-5 (5-lead Small Outline Transistor) | --- ## 2. Pin Configuration (SOT23-5) Because this specific part (RBN3TP) uses a 5-pin SOT23 package, it utilizes a multiplexed/reduced pinout compared to standard 8-pin EEPROMs. | Pin Number | Name | Description | | :--- | :--- | :--- | | **1** | **Q** | Serial Data Output | | **2** | **$V_{SS}$** | Ground | | **3** | **D** | Serial Data Input | | **4** | **C** | Serial Clock | | **5** | **$V_{CC}$** | Supply Voltage / Chip Select (Multiplexed) | *Note: In 5-pin packages, the Chip Select ($\bar{S}$) functionality is often managed through specific voltage level transitions or internal logic depending on the exact revision.* --- ## 3. Key Electronic Features ### A. SPI Protocol Support The device supports high-speed data transfer through a 4-wire bus (though pins are reduced in this package). It includes: * **Status Register:** Allows the user to check if a write cycle is in progress or if the memory is write-protected. * **Block Protection:** Parts of the memory can be software-protected against accidental overwriting. ### B. Write Operations * **Byte Write:** Can write a single 8-bit byte. * **Page Write:** Can write up to 32 bytes in a single instruction cycle, significantly improving throughput for large data sets. * **Self-Timed Write Cycle:** The device handles the internal high-voltage timing required to program the floating-gate cells (typically takes 5ms). ### C. Low Power Consumption * **Standby Mode:** When the chip is not selected, it enters a low-power state, drawing only a few microamps ($\mu A$). * **Wide Voltage Range:** The "R" in the part number signifies the ability to operate down to 1.8V, making it ideal for battery-powered devices. --- ## 4. Part Number Breakdown Understanding the suffix is crucial for replacement and design: | Suffix | Meaning | | :--- | :--- | | **M95320** | Base Series (SPI EEPROM, 32 Kbit) | | **-R** | Operating Voltage (1.8V to 5.5V) | | **BN** | Package (SOT23-5) | | **3** | Temperature Range (-40 to +125 °C) | | **TP** | Packing (Tape and Reel) | ---