The part number **R2-1-R/** typically refers to a high-performance, precision **Current Sense Resistor** (often manufactured by companies like Susumu or similar precision component brands). Below is a detailed breakdown of its electronic characteristics and specifications. --- ## 1. Component Overview The "R2" series is generally categorized as a **Metal Foil Low Resistance Chip Resistor**. These are designed for applications requiring high accuracy in power management and current detection. ### Technical Specifications | Feature | Typical Value | | :--- | :--- | | **Resistance Value** | 1.0 $\Omega$ (indicated by the '1') | | **Tolerance** | Usually $\pm 0.5\%$ or $\pm 1\%$ | | **Power Rating** | 0.25W to 1W (Size dependent) | | **Technology** | Metal Foil / Thick Film | | **Temperature Coefficient (TCR)** | $\pm 50$ to $\pm 100$ ppm/°C | --- ## 2. Key Characteristics ### A. Current Sensing Because the resistance is low (1 Ohm), this part is used to measure the current flowing through a circuit. By measuring the voltage drop across this resistor ($V = I \times R$), a microcontroller or power IC can calculate the exact amperage. ### B. High Precision Unlike standard carbon resistors, the metal foil construction ensures that the resistance value remains stable even as the component heats up during operation. ### C. Low Inductance The "R" series is designed with low parasitic inductance, making it suitable for high-frequency switching power supplies where "noise" must be minimized. --- ## 3. Application Use Cases * **DC-DC Converters:** Monitoring output current for feedback loops. * **Battery Management Systems (BMS):** Tracking charge and discharge rates in lithium batteries. * **Motor Control:** Detecting over-current conditions to prevent motor burnout. * **Mobile Devices:** Managing power distribution in smartphones and tablets. --- ## 4. Part Number Breakdown (Typical) | Segment | Meaning | | :--- | :--- | | **R2** | Series designation (Low resistance chip) | | **-1** | Resistance value (1.0 Ohm) | | **-R** | Packaging / Tolerance code (Tape and Reel) | | **/** | Ending suffix (often denotes RoHS compliance or specific reel size) | ---