### Technical Overview of LF2020BNP-R273 The **LF2020BNP-R273** is a high-performance **Common Mode Choke Coil** (Inductor) manufactured by Sumida. It is primarily used in power supply circuits to suppress electromagnetic interference (EMI) and noise. --- ### 1. Key Technical Specifications | Parameter | Value / Description | | :--- | :--- | | **Inductance** | 27.0 mH (Minimum) | | **Rated Current** | 0.6 A (Maximum) | | **DC Resistance** | 1.18 $\Omega$ (Maximum) | | **Core Material** | Ferrite | | **Configuration** | Vertical Mount / Through-hole | | **Operational Temp** | -40°C to +105°C | --- ### 2. Physical Characteristics * **Dimensions:** The "2020" series indicates a physical footprint approximately 20.5mm x 18.5mm, with a height of roughly 22.5mm. * **Winding Structure:** It features a dual-winding configuration on a single core. This allows the magnetic fields generated by the differential mode current to cancel out, while providing high impedance to common mode noise. * **Termination:** Lead-free (RoHS compliant) tinned copper leads for through-hole soldering on PCBs. --- ### 3. Functional Applications The LF2020BNP-R273 is designed for AC/DC power lines where noise suppression is critical: * **EMI Filtering:** It prevents high-frequency noise generated by switching power supplies from escaping back into the utility grid. * **Equipment Protection:** Protects sensitive internal electronics from incoming transient surges and noise from the power line. * **Common Use Cases:** * LED Lighting Drivers. * AC Adapters and Chargers. * Television and Home Appliance power boards. * Industrial Power Supplies. --- ### 4. Part Number Breakdown Understanding the nomenclature helps in identifying variants: 1. **LF:** Series Name (Line Filter). 2. **2020:** Physical dimensions/frame size. 3. **BNP:** Mounting style (Vertical, Plastic Header). 4. **R273:** Inductance code (273 = $27 \times 10^3$ µH = 27 mH). ---