The **SD20-R47-R** is a high-performance, surface-mount (SMD) power inductor commonly used in DC-DC converters and power management circuits. It belongs to the SD series manufactured by **Eaton (formerly Cooper Bussmann/Coiltronics)**. --- ### 1. Technical Specifications The part number "SD20-R47-R" follows a specific naming convention that defines its electrical characteristics: | Parameter | Specification | | :--- | :--- | | **Inductance** | 0.47 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.0215 Ω (Typical) | | **Irms (Heating Current)** | 4.34 Amps (approx.) | | **Isat (Saturation Current)** | 6.18 Amps (approx.) | | **Operating Temperature** | -40°C to +125°C | | **Shielding** | Magnetically Shielded | --- ### 2. Physical Characteristics The "SD20" designation refers to the physical size and footprint of the inductor. * **Dimensions:** Approximately 5.2mm x 5.2mm. * **Height:** 2.0mm (Low profile). * **Construction:** Ferrite core construction which provides high efficiency and minimizes EMI (Electromagnetic Interference). * **Termination:** Lead-free, RoHS compliant (indicated by the "-R" suffix). --- ### 3. Key Features & Applications #### Features * **High Power Density:** Provides high current handling in a small 5x5mm footprint. * **Low Core Loss:** Optimized for high-frequency switching power supplies. * **Magnetic Shielding:** Reduces interference with surrounding sensitive components on the PCB. #### Applications The SD20-R47-R is typically found in: 1. **Buck/Boost Converters:** Used for energy storage in voltage regulation. 2. **Mobile Devices:** Handheld instruments, GPS units, and smartphones due to the low-profile design. 3. **Computing:** Voltage Regulator Modules (VRMs) for laptops and tablets. 4. **LCD Displays:** Powering the backlight or internal logic circuits. --- ### 4. Part Number Breakdown ```text SD 20 - R47 - R | | | | | | | +-- RoHS Compliant | | +-------- Inductance Value: R47 = 0.47 microhenries (µH) | +------------- Size Code (Height/Footprint) +---------------- Series Name (Shielded Drum Inductor) ```