The **LR2010-R02FPB** is a high-power, low-resistance shunt resistor commonly manufactured by Welwyn (TT Electronics). It is specifically designed for current sensing applications where precision and thermal stability are critical. --- ## 1. Technical Specifications The following table highlights the primary electrical and physical characteristics of the component: | Feature | Specification | | :--- | :--- | | **Resistance Value** | 0.02 Ω (20 mΩ) | | **Tolerance** | ±1% (F) | | **Power Rating** | 1 Watt (at 70°C) | | **Package Size** | 2010 (Inches) / 5025 (Metric) | | **Temperature Coefficient (TCR)** | ±100 ppm/°C | | **Operating Temperature** | -55°C to +170°C | | **Technology** | Thick Film / Metal Alloy | --- ## 2. Part Number Breakdown Understanding the nomenclature helps in identifying variants: - **LR**: Series prefix (Low Resistance). - **2010**: Physical dimensions (0.20" x 0.10"). - **R02**: Resistance value (R denotes decimal, so 0.02 ohms). - **F**: Tolerance (F = ±1%). - **PB**: Packaging/Termination style (Lead-Free / Tin finish). --- ## 3. Key Electronic Functions ### A. Current Sensing The primary role of this part is to act as a **shunt resistor**. According to Ohm’s Law ($V = I \times R$), a small voltage drop occurs across the resistor as current flows through it. Because the resistance is a precise 0.02 Ω, a microcontroller or operational amplifier can measure this voltage to calculate the exact current in the circuit. ### B. Thermal Management The "LR" series is designed with a high power-to-size ratio. Its construction allows it to dissipate heat efficiently, preventing "thermal runaway" or resistance shifts that could lead to inaccurate sensor readings. ### C. Low Inductance Unlike wire-wound resistors, this surface-mount chip has very low self-inductance, making it suitable for high-frequency switching power supplies. --- ## 4. Common Applications * **Battery Management Systems (BMS):** Monitoring charge and discharge cycles in Li-ion packs. * **DC-DC Converters:** Providing feedback loops for voltage regulation. * **Motor Control:** Sensing phase currents to manage torque and speed. * **Power Tool Electronics:** Over-current protection circuits. ---