The designation **R100-R** is a specific part number convention typically used by manufacturers like **Susumu** (a leader in thin-film technology) or various generic resistor manufacturers. In the context of electronic components, this code refers to a **high-precision current sensing resistor**. --- ### 1. Decoding the Part Number The alphanumeric code "R100-R" contains specific data regarding the component's value and packaging: | Segment | Meaning | Detail | | :--- | :--- | :--- | | **R100** | Resistance Value | The 'R' acts as a decimal point. R100 = **0.100 $\Omega$** (or 100 m$\Omega$). | | **-R** | Packaging/RoHS | Usually indicates **Tape & Reel** packaging and **RoHS Compliance** (Lead-free). | ### 2. Technical Specifications While exact specs vary by series (e.g., RL, PR, or KRL series), a standard R100-R resistor generally follows these parameters: * **Type:** Current Sense / Low Ohmic Resistor. * **Technology:** Metal Foil or Thin Film (for high stability). * **Tolerance:** Commonly ±1% (F) or ±5% (J). * **Power Rating:** Typically ranges from 0.1W to 2W depending on the physical size (0603, 0805, 1206, etc.). * **Temperature Coefficient (TCR):** Usually very low (e.g., ±100ppm/°C) to ensure accuracy as the part heats up. ### 3. Applications The R100-R is primarily used in circuits where measuring current is necessary without dropping too much voltage. 1. **Battery Management Systems (BMS):** Monitoring charge and discharge cycles. 2. **DC-DC Converters:** Providing feedback to the controller to prevent overcurrent. 3. **Motor Controllers:** Detecting torque or load by measuring the current flowing through the motor. 4. **Power Supplies:** Implementing "Constant Current" modes. ### 4. Comparison Table: R100 vs. Standard Resistors | Feature | Standard Resistor (100 $\Omega$) | Current Sense Resistor (R100) | | :--- | :--- | :--- | | **Resistance** | High (100 Ohms) | Very Low (0.1 Ohms) | | **Primary Goal** | Limit Current / Voltage Divide | Measure Current | | **Heat Dissipation** | Low (usually) | High (designed for thermal efficiency) | | **Precision** | General | High (Thin film/Metal plate) | --- ### Summary for Purchasing If you are sourcing this part, ensure you verify the **Package Size** (e.g., SMD 1206 or 2512) and the **Wattage**, as "R100-R" defines the resistance value but the physical footprint and power limit are defined by the surrounding series codes (e.g., *RL1220-R100-R*).