The **NCSS20-R005TRF** is a surface-mount (SMD) current sense resistor. Components of this series are specifically engineered for precise current measurement by providing a very low resistance value with high stability. --- ## 1. Technical Specifications Below is a summary of the core electronic characteristics of the NCSS20-R005TRF: | Parameter | Specification | Note | | :--- | :--- | :--- | | **Resistance Value** | 0.005 Ω (5 mΩ) | Ultra-low resistance to minimize power loss | | **Tolerance** | ±1% (F) | High precision for sensing circuits | | **Power Rating** | 1 Watt | Maximum power dissipation at 70°C | | **Package Size** | 2010 (5025 Metric) | Surface mount dimensions: 5.0mm x 2.5mm | | **TC (Temp. Coeff.)** | ±100 ppm/°C | Stability across temperature variations | | **Construction** | Metal Plate / Thick Film | High reliability and high current handling | --- ## 2. Key Features * **Low Resistance:** At 5 milliohms, it minimizes the voltage drop across the component, ensuring that the sensor does not interfere significantly with the load circuit. * **High Power-to-Size Ratio:** The 2010 package allows for a 1W power rating, which is substantial for its footprint. * **AEC-Q200 Compliance:** Usually offered in automotive-grade versions (indicated by TRF sufix logic in some manufacturer lines), making it resistant to thermal shock and vibration. * **TCR (Temperature Coefficient of Resistance):** The low TCR ensures that the resistance value doesn't drift significantly as the component heats up during operation. --- ## 3. Typical Applications The NCSS20-R005TRF is primarily used in **Current Shunt Sensing** circuits. Common use cases include: 1. **Power Management Systems:** Monitoring battery discharge/charge rates in mobile devices or EVs. 2. **DC-DC Converters:** Providing feedback loops for over-current protection (OCP). 3. **Motor Control:** Sensing phase currents to manage torque and speed accurately. 4. **LED Drivers:** Ensuring a constant current flows through high-power LED strings. --- ## 4. How it Functions in a Circuit To measure current ($I$), the resistor is placed in series with the load. According to **Ohm's Law ($V = I \times R$)**, as current flows through the 0.005Ω resistor, a small voltage is generated across its terminals. ```python # Example Calculation for a 10A current: Resistance = 0.005 # Ohms Current = 10.0 # Amps Voltage_Drop = Current * Resistance # Output: 0.05V or 50mV Power_Dissipated = (Current**2) * Resistance # Output: 0.5 Watts (Well within the 1W rating) ```