The **M2RT-56-R** is a high-performance, shielded RJ45 modular jack integrated with internal magnetics (often referred to as a "MagJack"). It is primarily used in networking hardware to provide physical connectivity and electrical isolation for Ethernet interfaces. --- ### 1. Key Technical Specifications The following table outlines the core electronic and physical characteristics of the M2RT-56-R: | Feature | Specification | | :--- | :--- | | **Connector Type** | RJ45 (8P8C) | | **Data Rate Support** | 10/100 Base-T (Fast Ethernet) | | **Port Configuration** | Single Port (1x1), Right Angle (Tab Down) | | **Shielding** | Metal Shield with EMI fingers | | **LEDs** | Dual Integrated (Typically Green/Yellow) | | **Isolation Voltage** | 1500 Vrms | | **Mounting Type** | Through-Hole (THT) | --- ### 2. Internal Electronic Components The "MagJack" design integrates several discrete electronic components inside the plastic housing to save PCB space and improve EMI performance: * **Isolation Transformers:** Provides the 1500V galvanic isolation required by IEEE 802.3 standards to protect equipment from voltage surges. * **Common Mode Chokes:** Filters out high-frequency electromagnetic interference (EMI) and noise on the differential signal pairs. * **Termination Resistors:** Usually includes internal 75-ohm resistors (Bob Smith Termination) to reduce common-mode noise and match impedance. * **High-Voltage Capacitor:** A decoupling capacitor (typically 1000pF / 2kV) connects the transformer center taps to the chassis ground to bleed off static. --- ### 3. Pinout and Signal Routing The M2RT-56-R typically follows a standard pinout for 10/100 Ethernet. #### Signal Table (Typical) | Pin # | Signal | Description | | :--- | :--- | :--- | | 1 | TX+ | Transmit Data Positive | | 2 | TX- | Transmit Data Negative | | 3 | RX+ | Receive Data Positive | | 6 | RX- | Receive Data Negative | | 4, 5, 7, 8 | Terminated | Used for noise suppression/unused pairs | --- ### 4. Application Circuitry When designing a PCB with the M2RT-56-R, the following considerations are essential: 1. **LED Current Limiting:** The integrated LEDs require external resistors (typically 220Ω to 470Ω) depending on the VCC (3.3V or 5V). 2. **Chassis Ground:** The metal shield should be connected to a dedicated chassis ground, separate from the digital signal ground, usually coupled via a high-voltage capacitor. 3. **Differential Pairs:** The traces from the PHY chip to pins 1/2 and 3/6 must be routed as 100-ohm differential pairs.