The **M400173VSJ-R** is a specific part number typically associated with **DRAM (Dynamic Random Access Memory)** modules, often manufactured by companies like Micron or associated with specific industrial/embedded computing hardware (such as legacy VME or single-board computers). Below is a breakdown of the electronic characteristics and technical context for this component. --- ### 1. General Specifications Based on the nomenclature, this part belongs to the **Synchronous DRAM (SDRAM)** family, often used in networking, telecommunications, and industrial automation. | Feature | Description | | :--- | :--- | | **Component Type** | Dynamic RAM (DRAM) / SDRAM | | **Package Type** | SOJ (Small Outline J-lead) | | **Lead Count** | 40 or 50 Pins (depending on specific density) | | **Voltage** | Typically 3.3V (LVTTL compatible) | | **Interface** | Parallel, Synchronous | --- ### 2. Key Technical Attributes #### A. The "SOJ" Package The **VSJ** suffix in the part number indicates a **Small Outline J-lead** package. * **J-leads:** The pins curve inward under the body of the chip, resembling the letter "J". * **Space Efficiency:** This design was popular for high-density memory because it allowed for tighter spacing on the PCB and better thermal expansion handling compared to flat Gull-wing leads. #### B. Memory Architecture These chips are designed for high-speed data transfer synchronized with a system clock. * **Internal Banks:** Usually organized into 2 or 4 internal banks to allow concurrent operations. * **Refresh:** Requires periodic refresh cycles to maintain data integrity (standard for DRAM). #### C. Environmental and Reliability The **-R** suffix often denotes one of two things depending on the specific manufacturer's datasheet: 1. **RoHS Compliant:** The part is lead-free and meets environmental standards. 2. **Tape and Reel:** Packaging format for automated SMT (Surface Mount Technology) assembly. --- ### 3. Pinout and Signal Functions Common signals for this class of memory include: | Signal Name | Function | | :--- | :--- | | **CLK** | System Clock input | | **CKE** | Clock Enable (controls power-down modes) | | **CS#** | Chip Select (activates the device) | | **RAS# / CAS#** | Row and Column Address Strobes | | **WE#** | Write Enable | | **DQ0 - DQn** | Data Input/Output pins | --- ### 4. Typical Applications * **Legacy Computing:** Used in older server memory modules or workstation buffers. * **Embedded Systems:** Industrial controllers that require reliable, non-volatile (during operation) high-speed memory. * **Network Hardware:** Buffers for switches and routers. --- ### 5. Identification Code Breakdown While full internal datasheets are often proprietary to the OEM, the string `M400173` generally maps to: * **M:** Manufacturer (often Micron or Mitsubishi in legacy contexts). * **400:** Density/Organization indicator. * **VSJ:** Physical Package (SOJ). * **R:** Packaging/Compliance code.