The **SD25-3R3-R** is a surface-mount (SMD) power inductor part of the SD series manufactured by **Eaton (formerly Coiltronics/Bussmann)**. It is specifically designed for high power density and applications where space is limited. --- ### 1. Technical Specifications The part number follows a specific nomenclature. Below are the primary electrical and physical characteristics: | Parameter | Value | | :--- | :--- | | **Inductance** | 3.3 µH | | **Tolerance** | ±20% | | **Rated Current (Irms)** | 2.51 Amps | | **Saturation Current (Isat)** | 3.22 Amps | | **DC Resistance (DCR)** | 0.0336 Ω (Typical) | | **Shielding** | Magnetically Shielded | | **Package Size** | SD25 (Approx. 5.2 x 5.2 x 2.5 mm) | | **Operating Temp** | -40°C to +125°C | --- ### 2. Key Features * **Magnetic Shielding:** The component is shielded, which minimizes Electromagnetic Interference (EMI). This is crucial for dense PCB layouts where components are close to sensitive analog circuits. * **Low Profile:** The "25" in the series name indicates a height of approximately 2.5mm, making it suitable for thin consumer electronics. * **Ferrite Core:** Utilizes a ferrite core material that provides high efficiency and low core losses at high switching frequencies. * **RoHS Compliant:** The "-R" suffix indicates compliance with RoHS standards (lead-free). --- ### 3. Common Applications This inductor is typically used in power management circuits, including: * **DC-DC Converters:** Buck, Boost, and SEPIC topologies. * **Mobile Devices:** Smartphones, tablets, and handheld GPS units. * **Computer Peripherals:** Hard disk drives and SSD power rails. * **LED Drivers:** Small-scale lighting solutions requiring stable current. --- ### 4. Part Number Breakdown ```text SD 25 - 3R3 - R | | | | | | | +-- RoHS Compliant | | +------- Inductance Value (3.3 µH) | +------------ Size/Height Code (2.5mm) +--------------- Series Name (Shielded Drum) ```