The **LOR3E-R0075-K** is a specialized electronic component, specifically a **High-Power Current Sensing Resistor** (often referred to as a Shunt Resistor). It is designed to measure current flow by creating a small, predictable voltage drop across its terminals. --- ### 1. Part Number Breakdown While naming conventions can vary slightly by manufacturer (commonly associated with brands like **LIZ Electronics**), the alphanumeric code typically breaks down as follows: | Segment | Meaning | Detail | | :--- | :--- | :--- | | **LOR** | Series Code | Low Ohmic Resistor (Current Sense Series) | | **3E** | Case Size | Often corresponds to **2512** SMD package | | **R0075** | Resistance Value | **0.0075 Ohms** (or 7.5 mΩ) | | **K** | Tolerance | **±10%** (though some series use K for ±1%) | --- ### 2. Technical Specifications These components are engineered to handle high currents while maintaining stability. * **Resistance:** 7.5 milliohms (mΩ). * **Power Rating:** Typically **2 Watts to 3 Watts** (depending on the specific package thermal management). * **Technology:** Metal Foil or Metal Plate. Unlike standard thick-film resistors, these use a solid metal alloy to ensure low noise and high heat dissipation. * **Temperature Coefficient (TCR):** Usually very low (e.g., ±50ppm/°C to ±100ppm/°C) to ensure accuracy as the part heats up. --- ### 3. Key Features * **Low Resistance:** At 0.0075Ω, it minimizes power loss ($P = I^2R$) while allowing enough voltage drop for a microcontroller or Op-Amp to read. * **High Surge Capability:** Designed to withstand short-term overcurrent conditions without failing. * **AEC-Q200 Compliance:** Often produced to automotive standards for vibration and thermal shock resistance. --- ### 4. Common Applications This part is typically found in power management circuits where monitoring the "load" is critical: 1. **Battery Management Systems (BMS):** Monitoring charge and discharge cycles in Li-ion battery packs. 2. **Motor Control:** Detecting "stall" conditions or controlling torque by monitoring phase current. 3. **DC-DC Converters:** Used in the feedback loop to regulate output current. 4. **Overcurrent Protection:** Acting as a sensor for "e-fuses" to shut down a circuit if a short occurs. --- ### 5. Implementation Example To use this in a circuit, you would typically place it in series with the load. ```cpp // Example: Calculating Current (I) from Voltage Drop (V) // Formula: I = V / R float resistance = 0.0075; // 7.5 mOhms float measuredVoltage = 0.015; // 15mV measured across the resistor float current = measuredVoltage / resistance; // Result: 2.0 Amperes ```