The **LF2020BNP-R901** is a high-performance **Common Mode Choke Coil** manufactured by Sumida. It is designed primarily for noise suppression in power supply circuits, specifically to filter electromagnetic interference (EMI). --- ### 1. Technical Specifications The part number "R901" typically refers to the inductance and configuration series. Below are the standard characteristics for this component series: | Parameter | Specification | | :--- | :--- | | **Component Type** | AC Common Mode Choke | | **Inductance (Min)** | 9.0 mH | | **Rated Current** | ~0.7A - 1.0A (varies by thermal design) | | **DC Resistance (Max)** | ~0.72 Ω | | **Rated Voltage** | 250V AC / 50-60Hz | | **Operating Temp** | -40°C to +105°C | | **Mounting Type** | Through-hole (Vertical/Horizontal) | --- ### 2. Core Features * **High Impedance:** Provides excellent attenuation for high-frequency noise in the MHz range. * **Compact Design:** The "2020" series signifies a standard frame size that balances footprint with high inductance. * **Reliability:** Built using high-permeability ferrite cores to ensure stable performance across various temperatures. * **Safety Compliance:** Designed to meet international safety standards for power supplies (UL, VDE, etc.). --- ### 3. Circuit Application In an electronic circuit, the LF2020BNP-R901 is placed at the **Input Stage** (EMI Filter) of a Switch Mode Power Supply (SMPS). #### Pin Configuration (Standard 4-Pin) ```text Line In (1) o--[Coil]--o Line Out (2) Neutral In (4) o--[Coil]--o Neutral Out (3) ``` #### Primary Functions: 1. **Common Mode Noise Suppression:** It cancels out noise signals that travel in the same direction on both power lines. 2. **Prevents Feedback:** Prevents high-frequency switching noise generated by the device from leaking back into the AC utility grid. 3. **Surge Resistance:** Offers a minor level of protection against fast transients. --- ### 4. Typical Use Cases * **Consumer Electronics:** Televisions, Audio equipment, and PC Power Supplies. * **Industrial:** LED Drivers and small motor controllers. * **Appliances:** Washing machines and microwave ovens where EMI regulations are strict.