The **CDMC8D28NP-R39MC** is a high-performance, surface-mount (SMD) power inductor manufactured by **Sumida Corporation**. It is specifically designed for high-current applications where efficiency and low profile are critical. --- ### 1. Technical Specifications The part number encodes specific electrical and physical characteristics. Here is the breakdown: | Parameter | Value / Description | | :--- | :--- | | **Inductance** | 0.39 µH (indicated by "R39") | | **Tolerance** | ±20% (indicated by "M") | | **DC Resistance (DCR)** | ~1.60 mΩ (Typical) | | **Saturation Current ($I_{sat}$)** | ~31.0 A | | **Temperature Rise Current ($I_{rms}$)** | ~21.0 A | | **Dimensions (L x W x H)** | 9.2 x 8.3 x 3.0 mm | | **Core Material** | Metal Compound (Magnetic Iron Powder) | --- ### 2. Key Components & Construction The CDMC series utilizes a **metal compound molding technology**. This construction provides several advantages over traditional ferrite wire-wound inductors: * **Shielded Construction:** The magnetic powder core acts as a natural shield, minimizing Electromagnetic Interference (EMI) with surrounding components. * **Soft Saturation:** Unlike ferrite cores that lose inductance abruptly at high currents, the metal powder core exhibits "soft saturation," allowing the inductor to maintain stability during current spikes. * **Low DCR:** The use of thick copper wire ensures extremely low DC resistance, which reduces power loss and heat generation. --- ### 3. Typical Applications This inductor is commonly found in power management circuits for high-end electronics: 1. **DC/DC Converters:** Used in Point-of-Load (POL) modules for CPUs and GPUs. 2. **Voltage Regulator Modules (VRM):** Essential for high-current power stages in laptops and servers. 3. **Automotive Electronics:** Suitable for infotainment and ADAS systems due to its robust thermal performance. 4. **Battery Powered Devices:** High efficiency helps extend battery life in portable hardware. --- ### 4. Part Number Decoder Understanding the Sumida nomenclature for this specific part: | Code Segment | Meaning | | :--- | :--- | | **CDMC** | Series Name (Molded Power Inductor) | | **8D28** | Size code (approx. 8.0mm width, 2.8mm height) | | **NP** | Standard packaging/termination type | | **R39** | Value (0.39 microhenries) | | **M** | Tolerance (±20%) | | **C** | Taping/Reel code |