The **M2AS1-A442-R2** is a specific model identifier typically associated with **Active Optical Cables (AOC)** or specialized **QSFP28 to 4x SFP28 Breakout Cables**, often manufactured by companies like Mellanox (NVIDIA) or compatible high-performance networking vendors. Below is a breakdown of the electronic components and technical specifications for this part. --- ### 1. Core Technical Specifications This part is designed for high-density, high-speed data transmission in data centers. | Feature | Specification | | :--- | :--- | | **Form Factor** | QSFP28 to 4x SFP28 | | **Data Rate** | 100GbE (Aggregated) / 4x 25GbE (Split) | | **Media Type** | Active Optical Cable (AOC) | | **Reach** | Typically 1 to 30 Meters (depending on specific R-revision) | | **Wavelength** | 850nm (Multimode) | | **Protocol Support** | InfiniBand EDR, 100G Ethernet, Fibre Channel | --- ### 2. Key Electronic Components As an "Active" optical cable, the connector housings contain integrated circuits to convert electrical signals to optical signals and vice versa. #### A. The Transceiver ICs (DSP/CDR) * **Clock and Data Recovery (CDR):** The cable ends contain CDR chips to clean up signal jitter. This ensures that the high-speed 25Gbps signals remain stable over the length of the fiber. * **Driver ICs:** These drive the internal lasers (VCSELs) based on the electrical input from the switch/server. #### B. Optical Engines * **VCSEL (Vertical Cavity Surface Emitting Laser):** The light source used for transmitting data over the multimode fiber. * **PIN Photodiode:** The receiver component that converts incoming light pulses back into electrical current. #### C. EEPROM (Management Interface) * Contains the **I2C serial interface** data. This allows the host switch to identify the cable, manufacturer, part number, and monitor diagnostic information (DOM - Digital Optical Monitoring) such as temperature and voltage. --- ### 3. Functional Pinout Mapping The M2AS1-A442-R2 acts as a "Hydra" or breakout cable. The electronic mapping is as follows: | QSFP28 Side (100G) | SFP28 Side (4x 25G) | Function | | :--- | :--- | :--- | | Lane 1 (TX1+/-, RX1+/-) | SFP Connection 1 | 25Gbps Data Stream | | Lane 2 (TX2+/-, RX2+/-) | SFP Connection 2 | 25Gbps Data Stream | | Lane 3 (TX3+/-, RX3+/-) | SFP Connection 3 | 25Gbps Data Stream | | Lane 4 (TX4+/-, RX4+/-) | SFP Connection 4 | 25Gbps Data Stream | --- ### 4. Application Context * **Network Aggregation:** Connecting a 100G switch port to four individual 25G servers. * **Power Consumption:** Because it is an AOC, it consumes more power than a Passive Direct Attach Copper (DAC) cable but significantly less than individual optical transceivers with patch cables. * **Weight/Airflow:** Much thinner and lighter than copper equivalents, allowing for better cooling in high-density racks.