The **DR125-3R3-R** is a high-power, shielded drum core inductor manufactured by **Eaton (formerly Bussmann/Coiltronics)**. It is part of the DR series, which is designed for high efficiency and high power density in power electronic circuits. --- ### ## Technical Specifications Below are the primary electrical and physical characteristics of the DR125-3R3-R: | Parameter | Specification | | :--- | :--- | | **Inductance** | 3.3 µH | | **Tolerance** | ±20% | | **Rated Current (Irms)** | 10.1 Amperes | | **Saturation Current (Isat)** | 16.0 Amperes | | **DC Resistance (DCR)** | 0.0069 Ohms (Max) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 12.5mm x 12.5mm x 6.0mm | | **Shielding** | Magnetically Shielded | --- ### ## Key Features 1. **High Current Capacity**: Designed to handle high saturation currents (up to 16A), making it ideal for modern power-hungry processors and battery charging circuits. 2. **Magnetic Shielding**: The inductor is enclosed in a ferrite sleeve. This minimizes **Electromagnetic Interference (EMI)**, preventing the inductor from interfering with nearby sensitive components on the PCB. 3. **Low DCR**: With a maximum DC resistance of only 6.9mΩ, this part minimizes power loss through heat, contributing to higher overall system efficiency. 4. **Robust Construction**: The "DR125" designation indicates a physical size of roughly 12.5mm square, providing a stable footprint for Surface Mount Technology (SMT). --- ### ## Common Applications * **Buck/Boost Converters**: Used as the energy storage element in DC-DC converters for laptops, servers, and networking equipment. * **Voltage Regulator Modules (VRM)**: High-current phases for CPU or GPU power delivery. * **Battery Powered Systems**: Essential in handheld devices where high efficiency is required to extend battery life. * **Output Filter**: Used to smooth out ripple current in switching power supplies. --- ### ## Part Number Breakdown The part number follows a specific nomenclature used by Eaton: * **DR**: Series name (Drum Core, Shielded). * **125**: Physical size (12.5mm x 12.5mm x 6.0mm). * **3R3**: Inductance value ($3.3 \mu H$). The 'R' acts as a decimal point. * **-R**: RoHS compliant (Lead-free).