## Electronic Specifications: RL2550W-R050G The **RL2550W-R050G** is a high-power, low-resistance chip resistor commonly used for current sensing applications. It is part of the **RL Series** manufactured by Susumu (or similar vendors following the same naming convention), designed specifically for precision and stability in power management circuits. --- ### 1. Key Technical Specifications | Parameter | Specification | Description | | :--- | :--- | :--- | | **Resistance Value** | 50 mΩ (0.050 Ω) | The electrical resistance at 25°C. | | **Power Rating** | 2.0 Watts | The maximum power it can dissipate safely. | | **Tolerance** | ±2% (G) | The allowable variance from the nominal resistance. | | **Temperature Coefficient** | ±100 ppm/°C | How much the resistance changes with temperature. | | **Case Size** | 2550 (Metric) / 1020 (Inch) | Physical dimensions (Long-side terminal). | | **Technology** | Thick Film | Constructed using thick film resistive elements. | --- ### 2. Breakdown of the Part Number Understanding the nomenclature helps identify the physical and electrical characteristics: * **RL**: Series prefix (Low resistance chip resistors). * **2550**: The physical dimensions. This is a **Long-side terminal** package (1020 in inches, 2550 in metric), meaning the terminals are on the long sides to improve heat dissipation and reduce ESL (Equivalent Series Inductance). * **W**: Power rating code (usually indicating the 2.0W "Wide" or "High Power" variant). * **R050**: The resistance value. "R" acts as the decimal point (0.050 Ohms). * **G**: Tolerance code representing **±2%**. --- ### 3. Applications and Features #### Features * **High Power Dissipation:** Because the terminals are on the long sides, the heat path to the PCB is shorter and wider, allowing it to handle up to 2W in a relatively small footprint. * **Low Inductance:** The geometry reduces parasitic inductance, making it suitable for high-frequency switching power supplies. * **Current Sensing:** Specifically designed to create a small voltage drop that can be measured by a controller to determine current flow. #### Typical Use Cases 1. **DC-DC Converters:** Sensing output current for regulation. 2. **Battery Management Systems (BMS):** Monitoring charge and discharge cycles. 3. **Motor Control:** Detecting over-current conditions to protect the motor. 4. **AC Adapters:** Power monitoring in consumer electronics. --- ### 4. Comparison: Long-Side vs. Short-Side Terminals | Feature | RL2550 (Long-Side) | Standard 2512 (Short-Side) | | :--- | :--- | :--- | | **Heat Dissipation** | Excellent (Wide path) | Moderate | | **Solder Joint Stress** | Lower (due to geometry) | Higher | | **ESL (Inductance)** | Very Low | Higher | | **Power Density** | Higher | Lower |