The **DR74-221-R** is a high-performance, shielded power inductor manufactured by **Eaton (formerly Bussmann)**. It belongs to the DR Series, which is characterized by its high power density and electromagnetic interference (EMI) shielding. --- ### ## Technical Specifications The following table summarizes the key electrical and physical characteristics of the DR74-221-R: | Parameter | Value | | :--- | :--- | | **Inductance** | 220 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.825 Ω (Max) | | **Rated Current (Irms)** | 0.68 Amps | | **Saturation Current (Isat)** | 0.83 Amps | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 7.6mm x 7.6mm x 4.35mm | | **Shielding** | Magnetically Shielded | --- ### ## Key Features * **Magnetically Shielded:** The drum core is enclosed, which significantly reduces EMI. This makes it ideal for use near sensitive components on a PCB. * **High Power Density:** Designed to handle significant current relative to its small surface-mount footprint. * **Ferrite Core Construction:** Provides high efficiency and low core losses at switching frequencies. * **RoHS Compliant:** The "-R" suffix indicates that the part is lead-free and meets RoHS environmental standards. --- ### ## Common Applications The DR74-221-R is typically used in power management circuits where voltage regulation and noise filtering are required: 1. **DC-DC Converters:** Used as a storage element in buck (step-down) or boost (step-up) converters. 2. **Computer Peripherals:** Found in laptops, servers, and storage drives. 3. **Battery Powered Devices:** Ideal for handheld electronics due to its compact size and efficiency. 4. **LED Lighting:** Used in driver circuits to stabilize current. --- ### ## Understanding the Part Number The part number can be broken down to understand its properties: * **DR:** Series name (Drum Core, Shielded). * **74:** Dimensional code (Approx. 7.6mm x 4.35mm). * **221:** Inductance value code. The first two digits (22) are the value, and the third (1) is the number of zeros. (22 x 10^1 = 220 µH). * **R:** RoHS compliant.