The **FP0705R1-R18-R** is a high-current, shielded drum core inductor designed specifically for use in high-frequency power applications. It is commonly used in Voltage Regulator Modules (VRMs) for servers, workstations, and networking equipment. --- ## 1. Part Number Breakdown Understanding the nomenclature helps identify its specific electronic characteristics: | Code Segment | Meaning | Description | | :--- | :--- | :--- | | **FP0705** | Series & Size | Indicates the "Flat-Pac" series with dimensions approx. 7.0 x 7.0 x 5.0 mm. | | **R1** | Version | Design revision or manufacturing version. | | **R18** | Inductance | **0.18 µH** (R denotes decimal point). | | **-R** | RoHS | Compliant with RoHS (Lead-free). | --- ## 2. Key Specifications These values define how the part behaves in a circuit: | Parameter | Value | Details | | :--- | :--- | :--- | | **Inductance ($L$)** | 0.18 µH | Low inductance for fast transient response. | | **DCR (Max)** | ~0.46 mΩ | Extremely low DC resistance to minimize power loss. | | **Saturation Current ($I_{sat}$)** | ~54 A | The current level where inductance drops by 20%. | | **RMS Current ($I_{rms}$)** | ~38 A | The maximum continuous current based on heat rise. | | **Operating Temp** | -40°C to +125°C | Standard industrial/server temperature range. | --- ## 3. Core Features & Usage ### A. Design Characteristics * **Shielded Construction:** The inductor is magnetically shielded to reduce Electromagnetic Interference (EMI), which is critical in dense PCB layouts. * **High Frequency:** Optimized for switching frequencies up to several megahertz (MHz). * **Flat-Pac Technology:** Uses a flat wire or specialized core shape to maximize current density in a small footprint. ### B. Common Applications * **Multi-phase VRMs:** Used in the power delivery stage for CPUs and GPUs. * **DC-DC Converters:** High-efficiency buck or boost regulators. * **Server/Base Station Power:** Suitable for high-reliability infrastructure. --- ## 4. Typical Footprint ```text [ 7.0 mm ] +--------------+ | | | R18 | [ 7.0 mm ] | | +--------------+ [ 5.0 mm Height ] ```