The **CDMC8D28NP-R18MC** is a high-performance, surface-mount (SMD) power inductor manufactured by **Sumida**. It belongs to the CDMC series, which is characterized by its metal composite core construction. --- ### 1. Technical Specifications The part number encodes specific characteristics of the component. Below are the primary technical parameters: | Parameter | Specification | | :--- | :--- | | **Inductance** | 0.18 µH | | **Tolerance** | ±20% (M) | | **DC Resistance (Max)** | 1.80 mΩ | | **Saturation Current (Isat)** | ~34.0 A (at 20°C) | | **Temperature Rise Current (Irms)** | ~25.0 A | | **Operating Temperature** | -40°C to +125°C | | **Dimensions (LxWxH)** | 8.4 x 8.0 x 3.0 mm | --- ### 2. Key Construction Features The "Metal Composite" structure provides several advantages over traditional ferrite core inductors: * **Magnetic Shielding:** The molded construction naturally shields the component, minimizing Electromagnetic Interference (EMI) with surrounding components. * **Soft Saturation:** Unlike ferrite cores that drop inductance sharply when exceeding current limits, this metal powder core exhibits a gradual (soft) saturation curve. * **High Current Density:** The flat-wire or specialized coil design inside allows for extremely low DC resistance (DCR), reducing heat generation during high-current operation. * **Robustness:** The molded body provides high resistance to mechanical shock and vibration. --- ### 3. Application Areas This specific inductor is designed for high-efficiency power supplies where space is limited but current demands are high. * **DC/DC Converters:** Ideal for Point-of-Load (POL) converters in laptops and servers. * **Voltage Regulator Modules (VRM):** Used in CPU/GPU power stages due to the very low 0.18µH inductance, which allows for fast transient response. * **Automotive/Industrial:** High-temperature stability makes it suitable for advanced driver-assistance systems (ADAS) or industrial control boards. --- ### 4. Part Number Breakdown Understanding the nomenclature helps in identifying variants: | Code | Meaning | | :--- | :--- | | **CDMC** | Series Name (Metal Composite Inductor) | | **8D28** | Case Size (Approx. 8x8x2.8mm) | | **NP** | Lead-free / RoHS Compliant | | **R18** | Inductance Value (R18 = 0.18 µH) | | **M** | Tolerance (±20%) | | **C** | Packing (Carrier Tape/Reel) |