## Technical Overview: DR73-220-R Inductor The **DR73-220-R** is a high-power density, shielded drum core inductor manufactured by **Eaton (formerly Bussmann/Coiltronics)**. It is part of the DR series, designed for surface mount (SMD) applications where space is limited and electromagnetic interference (EMI) must be minimized. --- ### 1. Key Technical Specifications The alphanumeric code "220" indicates the inductance value, and "R" signifies RoHS compliance. | Parameter | Specification | | :--- | :--- | | **Inductance** | 22.0 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.0888 Ω (Typical) | | **Rated Current (Irms)** | 1.69 Amps | | **Saturation Current (Isat)** | 1.83 Amps | | **Operating Temperature** | -40°C to +125°C | | **Package Size** | DR73 (approx. 7.6 x 7.6 x 3.55 mm) | | **Shielding** | Magnetically Shielded | --- ### 2. Physical Construction and Design The DR73-220-R features a specific architecture to balance performance and size: * **Ferrite Drum Core:** Provides high permeability and handles high frequency switching efficiently. * **Magnetic Shielding:** A ferrite sleeve surrounds the winding. This traps the magnetic flux, preventing the inductor from interfering with nearby sensitive components and reducing audible noise. * **Surface Mount Design:** Features a flat top for high-speed automated "pick and place" assembly and robust solder pads for board stability. --- ### 3. Common Applications Due to its shielding and current handling, the DR73-220-R is typically found in: 1. **DC-DC Converters:** Used as a storage element in Buck, Boost, or SEPIC converters. 2. **Power Supplies:** Common in laptop adapters, LED drivers, and distributed power systems. 3. **Noise Filtering:** Acting as a low-pass filter to smooth out ripples in power lines for telecommunications and industrial equipment. 4. **Battery Powered Devices:** Ideal for handheld electronics where high efficiency and small footprints are required. --- ### 4. Interpretation of the Part Number * **DR:** Series name (Drum Core, Shielded). * **73:** Size code (7.6mm width, 3.5mm height). * **220:** Inductance value. The first two digits (22) are the value, the third digit (0) is the multiplier ($10^0$). Result: $22 \times 1 = 22$ µH. * **R:** RoHS compliant (Lead-free).