The **WW12RR010FQL** is a specialized electronic component manufactured by **Walsin Technology Corporation**. It belongs to the category of **Current Sensing Surface Mount Resistors (SMD)**. Below is a detailed breakdown of its specifications and functions. --- ### 1. Technical Specifications The part number follows a specific nomenclature that defines its physical and electrical characteristics. | Parameter | Specification | Description | | :--- | :--- | :--- | | **Series** | WW12 | 1206 Case Size (approx. 3.2 x 1.6 mm) | | **Material/Type** | R | Low Ohm (Metal Strip / Thick Film) | | **Resistance Value** | R010 | 0.010 $\Omega$ (10 m$\Omega$) | | **Tolerance** | F | $\pm 1\%$ | | **Packaging Code** | Q | 7" Reel / Paper Tape | | **Termination** | L | Lead-free (RoHS Compliant) | | **Power Rating** | 0.25W - 0.5W | Standard for 1206 size | --- ### 2. Core Functional Role This component is primarily used for **Current Sensing**. Because it has a very low resistance value (10 m$\Omega$), it is placed in series with a load to measure current flow using **Ohm’s Law ($V = I \times R$)**. * **Operation:** As current passes through the resistor, a small voltage drop occurs. * **Measurement:** A Power Management IC (PMIC) or Microcontroller senses this voltage drop to calculate the exact current being drawn by the system. * **Protection:** It is often used to trigger "Overcurrent Protection" (OCP) if the voltage drop exceeds a safety threshold. --- ### 3. Key Features * **Low TCR (Temperature Coefficient of Resistance):** Designed to maintain its resistance value even as the component heats up during operation. * **High Reliability:** The WW series is built to handle repetitive pulse currents. * **Compact Footprint:** The 1206 form factor allows for high-density PCB placement. --- ### 4. Common Applications 1. **Battery Management Systems (BMS):** Monitoring charge and discharge rates in laptops or power tools. 2. **DC-DC Converters:** Providing feedback loops for voltage regulation. 3. **Motor Control:** Sensing stall currents or load variations in small motors. 4. **Consumer Electronics:** Power adapters and chargers for mobile devices. ---