The **SD20-4R7-R** is a high-performance, low-profile surface mount (SMD) power inductor. It is part of the SD series manufactured by **Eaton (formerly Cooper Bussmann)**. These components are primarily used for energy storage and filtering in DC-DC converters. --- ### 1. Technical Specifications The part number follows a specific nomenclature where "4R7" represents the inductance value and "R" signifies RoHS compliance. | Parameter | Specification | | :--- | :--- | | **Inductance** | 4.7 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.0544 Ω (Typical) | | **Rated Current (Irms)** | 1.58 Amps | | **Saturation Current (Isat)** | 1.48 Amps | | **Operating Temperature** | -40°C to +125°C | | **Dimensions (L x W x H)** | 5.2mm x 5.2mm x 2.0mm | --- ### 2. Key Features * **Magnetic Shielding:** The inductor is magnetically shielded, which minimizes Electromagnetic Interference (EMI) and prevents noise from affecting nearby sensitive components on the PCB. * **Low Profile:** With a height of only 2.0mm, it is ideal for thin electronic devices like smartphones, tablets, and wearable tech. * **Ferrite Core:** Utilizes a ferrite core material that provides high efficiency and low core losses at high frequencies. * **Rugged Construction:** Designed to withstand high-temperature reflow soldering processes. --- ### 3. Common Applications The SD20-4R7-R is typically found in circuits requiring efficient power management: 1. **DC-DC Converters:** Buck, Boost, and SEPIC topologies. 2. **Portable Electronics:** Battery-powered devices where space is limited. 3. **Computer Peripherals:** Used in SSDs, VGA cards, and motherboards. 4. **LED Drivers:** Providing stable current for lighting applications. --- ### 4. Part Number Breakdown ```text SD 20 - 4R7 - R | | | | | | | └── RoHS Compliant | | └──────── Inductance Value (4.7 microhenries) | └───────────── Size/Series Code (5.2 x 5.2 x 2.0 mm) └──────────────── Series Name (Shielded Drum Inductor) ```