The **DR124-221-R** is a specific model of power inductor manufactured by **Eaton** (formerly Cooper Bussmann/Coiltronics). It is part of the DR series, known for its high power density and shielded construction. --- ### 1. Key Technical Specifications The part number "221" indicates its inductance value, and "R" signifies RoHS compliance. | Parameter | Value | | :--- | :--- | | **Inductance** | 220 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.505 Ω (Max) | | **Irms (Rated Current)** | 0.95 Amps | | **Isat (Saturation Current)** | 1.15 Amps | | **Operating Temperature** | -40°C to +125°C | | **Dimensions** | 12.5mm x 12.5mm x 4.5mm | --- ### 2. Physical Construction The DR124 series is engineered for durability and efficiency: * **Ferrite Core:** High-frequency material that minimizes core losses. * **Magnetically Shielded:** The inductor is enclosed in a ferrite sleeve. This reduces **Electro-Magnetic Interference (EMI)**, preventing the inductor from interfering with nearby sensitive components on the PCB. * **Surface Mount (SMT):** Designed for automated pick-and-place assembly. --- ### 3. Common Applications Due to its high inductance (220 µH) and medium current rating, the DR124-221-R is typically found in: * **DC-DC Converters:** Used as an energy storage element in Buck, Boost, or SEPIC converters. * **Power Supplies:** Common in industrial electronics, LED drivers, and computer peripherals. * **Filter Inductors:** Used in LC circuits to smooth out voltage ripples and reduce noise in power lines. --- ### 4. Part Number Breakdown Understanding the nomenclature helps in selecting alternates: * **DR:** Series Name (Drum Core). * **124:** Size Code (approx. 12.5mm x 12.5mm x 4.5mm). * **221:** Inductance Code (22 followed by 1 zero = 220). * **-R:** RoHS Compliant (Lead-free).