The **LOR3E-R0075-H** is a high-precision, low-resistance current sense resistor. It is part of the **LOR series** (typically manufactured by companies like Cyntec), designed specifically for power management and current sensing applications in compact electronic circuits. --- ### 1. Key Technical Specifications The model number encodes several critical parameters: | Parameter | Specification | Description | | :--- | :--- | :--- | | **Resistance Value** | 7.5 mΩ (0.0075 Ω) | Indicated by "R0075" | | **Tolerance** | ±3% (typically) | Precision level for current measurement | | **Power Rating** | 3 Watts | The maximum power dissipation capacity | | **Size / Footprint** | 2512 (approx.) | Large surface mount (SMD) package to handle heat | | **Construction** | Metal Alloy | Low-inductance, high-stability metal strip | --- ### 2. Functional Components & Characteristics #### A. Metal Strip Technology Unlike standard thick-film resistors, the LOR3E uses a **metal alloy plate**. This provides superior thermal stability and ensures that the resistance does not change significantly as the component heats up (Low TCR - Temperature Coefficient of Resistance). #### B. Low Inductance Because this is a "Shunt" resistor, it is designed with a low-inductance structure. This is vital for high-frequency switching power supplies to prevent voltage spikes and measurement errors. #### C. Heat Dissipation The "3E" designation often refers to the enhanced power rating (3W). The physical size and the metal construction allow it to dissipate heat efficiently into the PCB copper traces. --- ### 3. Common Applications 1. **Battery Management Systems (BMS):** Monitoring the charge and discharge current of Lithium-ion batteries. 2. **DC-DC Converters:** Providing feedback loops for current-mode control. 3. **Motor Controllers:** Sensing the phase current to protect the motor from overcurrent conditions. 4. **Power Inverters:** Used in solar or automotive electronics to measure high-power throughput. --- ### 4. Circuit Implementation (Typical Shunt Layout) In a circuit, the LOR3E-R0075-H is placed in series with the load. The voltage drop across it is measured using a Kelvin connection (4-terminal sensing) to ensure accuracy. ```cpp // Ohm's Law Calculation Example Voltage_Drop (V) = Current (I) * Resistance (R) If Current = 10 Amps: V = 10A * 0.0075Ω = 0.075V (75mV) ```