### Technical Overview of SD20-470-R The **SD20-470-R** is a specific model of power inductor manufactured by **Eaton (formerly Coiltronics)**. It is part of the SD20 series, which is characterized by its low profile, high power density, and shielded construction. --- ### Key Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 47.0 µH | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 0.69 Amps (Typical) | | **Saturation Current (Isat)** | 0.54 Amps (Typical) | | **DC Resistance (DCR)** | 0.441 Ω (Maximum) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 5.2mm x 5.2mm x 2.0mm | --- ### Core Characteristics #### 1. Magnetic Shielding The "SD" in the series stands for **Shielded**. This means the inductor is designed to contain its magnetic field. This is critical in modern electronics to: * Prevent Electromagnetic Interference (EMI) with neighboring components. * Reduce audible noise in sensitive audio circuits. #### 2. Ferrite Core Construction The part utilizes a ferrite drum core. Ferrite is preferred for power applications because it offers high magnetic permeability while maintaining low eddy current losses at high frequencies. #### 3. Surface Mount Technology (SMT) The part is designed for automated PCB assembly. It features a rugged base and flat top for reliable "pick and place" machine handling and infrared (IR) reflow soldering. --- ### Common Applications The SD20-470-R is typically found in power management circuits where space is limited. * **DC-DC Converters:** Specifically Buck, Boost, and SEPIC topologies. * **Portable Electronics:** Used in smartphones, tablets, and handheld GPS units. * **LED Drivers:** Providing stable current for lighting systems. * **Computer Peripherals:** Used in hard disk drives (HDD) and solid-state drives (SSD) power rails. --- ### Part Number Breakdown `SD20-470-R` * **SD:** Series name (Shielded Drum). * **20:** Size code (refers to the 2.0mm height). * **470:** Inductance value (47 followed by 0 zeros = 47µH). * **-R:** RoHS compliant (Lead-free).