The **SD25-151-R** is a high-power, shielded surface-mount (SMD) inductor manufactured by Eaton (formerly Cooper Bussmann/Coiltronics). It is part of the SD25 series, known for its low profile and high energy storage capabilities. --- ## 1. Technical Specifications The part number "151" indicates the inductance value, while the "R" signifies RoHS compliance. | Parameter | Specification | | :--- | :--- | | **Inductance** | 150 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.435 Ω (Typical) | | **Irms (Rated Current)** | 0.65 Amps | | **Isat (Saturation Current)** | 0.81 Amps | | **Shielding** | Ferrite Drum Core (Shielded) | | **Operating Temperature** | -40°C to +125°C | --- ## 2. Key Features * **Magnetic Shielding:** The component is shielded, which minimizes Electromagnetic Interference (EMI). This is crucial for densely packed circuit boards where noise can affect nearby components. * **Low Profile:** The "25" in the series name refers to its physical size (approx. 5.2mm x 5.2mm x 2.5mm), making it suitable for compact electronic devices. * **High Power Density:** Despite its small footprint, it can handle significant current, making it ideal for power conversion stages. --- ## 3. Common Applications The SD25-151-R is primarily used in power management circuits where voltage needs to be regulated or filtered. 1. **DC-DC Converters:** Used in buck (step-down) or boost (step-up) converters to store energy during the switching cycle. 2. **Buck-Boost Regulators:** Ideal for battery-powered devices where the input voltage varies. 3. **Noise Filtering:** Acting as a low-pass filter to smooth out ripples in power supplies. 4. **Consumer Electronics:** Found in tablets, LED drivers, and portable medical devices. --- ## 4. Part Number Breakdown Understanding the nomenclature helps in identifying variants: * **SD:** Series name (Shielded Drum). * **25:** Size code (refers to dimensions/height). * **151:** Inductance value ($15 \times 10^1 = 150 \mu H$). * **R:** RoHS compliant / Lead-free.