The **SD25-150-R** is a specific surface-mount power inductor manufactured by **Eaton (formerly Cooper Bussmann)**. It belongs to the SD25 series, which is characterized by its low profile, high power density, and shielded construction. --- ### 1. Technical Specifications The part number "SD25-150-R" can be broken down to understand its core electronic properties: | Parameter | Value / Specification | | :--- | :--- | | **Series** | SD25 (Standard profile, shielded drum core) | | **Inductance** | 15.0 µH | | **Tolerance** | ±20% | | **DCR (Direct Current Resistance)** | ~0.119 Ω (Typical) | | **Irms (Rated Current)** | ~1.42 Amps | | **Isat (Saturation Current)** | ~1.28 Amps | | **Shielding** | Ferrite shielded (Magnetic shielding) | | **Operating Temperature** | -40°C to +125°C | --- ### 2. Physical Characteristics The SD25 series is designed for automated assembly on printed circuit boards (PCBs). * **Footprint:** Approximately 5.2mm x 5.2mm. * **Height:** 2.5mm maximum (Low profile). * **Packaging:** Tape and Reel (indicated by the "-R" suffix). * **Termination:** Lead-free, RoHS compliant matte tin over copper. --- ### 3. Key Electronic Functions The SD25-150-R serves several critical roles within an electronic circuit: #### A. Energy Storage In DC-DC converters (Buck, Boost, or SEPIC), this inductor stores energy in its magnetic field during the "on" cycle of the switching transistor and releases it to the load during the "off" cycle. #### B. Noise Filtering Because inductors resist changes in current, the SD25-150-R acts as a low-pass filter, smoothing out ripples in the output voltage and blocking high-frequency electromagnetic interference (EMI). #### C. Magnetic Shielding The "Shielded" design means the magnetic flux is mostly contained within the ferrite body. This is crucial for high-density boards to prevent the inductor from interfering with nearby sensitive components. --- ### 4. Common Applications * **Mobile Devices:** Power management for smartphones and tablets. * **Computing:** DC-DC converters for CPUs and video cards. * **Industrial:** LED drivers and portable instrumentation. * **Consumer Electronics:** Set-top boxes and game consoles. --- ### 5. Part Number Decoding ```text S D 25 - 150 - R | | | | | | | | | +-- RoHS Compliant / Tape & Reel | | | +------- Inductance Code (150 = 15 x 10^0 = 15µH) | | +------------- Size/Profile Code (2.5mm high) +--+---------------- Series Name (Shielded Drum) ```