The **M2REB-R2D-R2** is a specialized electronic component, specifically a **M.2 (NGFF) to PCIe riser card/adapter**, often used in industrial computing, server environments, or high-performance desktop setups. Below is a detailed breakdown of its electronic characteristics and specifications. --- ### 1. General Specifications The device acts as a bridge between an M.2 slot and a standard PCIe interface. It is frequently associated with **ASRock Industrial** or similar OEM manufacturers for integration into Small Form Factor (SFF) motherboards. | Feature | Specification | | :--- | :--- | | **Form Factor** | M.2 2280 (80mm length) | | **Input Interface** | M.2 Key-M (PCIe x4 Signal) | | **Output Interface** | PCIe x4 Slot (Open-ended or standard) | | **Revision** | R2.0 / R2D (Indicates specific PCB layout updates) | | **Compatibility** | NVMe-based M.2 slots | --- ### 2. Key Electronic Components The PCB consists of several critical stages to ensure data integrity and power delivery: * **Differential Pair Routing:** Since this carries high-speed PCIe Gen3 or Gen4 signals, the traces are impedance-matched (typically 85-100 ohms) to prevent signal reflection. * **Power Conversion (Buck/Boost):** M.2 slots provide 3.3V. If the adapter supports external devices requiring 12V, it may include a small DC-DC converter or require an external 4-pin/SATA power input. * **Decoupling Capacitors:** Small MLCC (Multi-Layer Ceramic Capacitors) are placed near the PCIe gold fingers to filter high-frequency noise and stabilize the voltage rails. * **Status LEDs:** Often includes SMD LEDs to indicate "Power Good" and "Link Activity." --- ### 3. Pinout and Signal Mapping The adapter maps the high-speed pins from the M.2 Key-M standard directly to the PCIe x4 connector pins. | Signal Type | Description | | :--- | :--- | | **PETp/n (0-3)** | PCIe Transmit Differential Pairs | | **PERp/n (0-3)** | PCIe Receive Differential Pairs | | **REFCLKp/n** | Reference Clock (100MHz) | | **PERST#** | Fundamental Reset Signal | | **WAKE#** | Power management/wake signal | --- ### 4. Common Use Cases 1. **GPU External Connection:** Used to connect a graphics card to a laptop or NUC that only has an internal M.2 slot. 2. **Storage Expansion:** Converting an M.2 slot into a PCIe slot to add high-speed networking cards (10GbE) or RAID controllers. 3. **Mining Rigs:** Adapting motherboard M.2 slots to support additional USB-to-PCIe risers. --- ### 5. Installation Note > **Warning:** Ensure the M.2 slot on the motherboard is **Key-M (PCIe)** and not **Key-B (SATA)**. This adapter will not function in a SATA-only M.2 slot as it lacks the necessary PCIe lanes.