The **CF252018-R27** is a specific type of **Surface Mount (SMD) Wire-wound Inductor**. The part number follows a standard industry naming convention that defines its physical dimensions and electrical properties. ### 1. Part Number Breakdown The nomenclature typically breaks down as follows: | Component Segment | Meaning | Specification | | :--- | :--- | :--- | | **CF** | Series Code | High-frequency chip inductor (Ceramic or Ferrite core) | | **252018** | Case Size (Metric) | 2.5mm x 2.0mm x 1.8mm | | **R27** | Inductance Value | 0.27 µH (270 nH) | --- ### 2. Technical Specifications Inductors in this category are designed for high-reliability signal filtering and power management in compact circuits. * **Inductance:** 0.27 µH (The "R" acts as a decimal point). * **Tolerance:** Commonly ±5% (J), ±10% (K), or ±20% (M). * **Core Material:** Usually **Ferrite**, which provides higher inductance values and better magnetic shielding compared to ceramic. * **Construction:** Wire-wound. A fine copper wire is wrapped around a core to create a coil, offering lower DC resistance (DCR) than multilayer types. --- ### 3. Key Electrical Characteristics While specific values depend on the manufacturer (e.g., Chilisin, Bourns, or generic equivalents), the typical parameters for an R27 inductor are: 1. **Self-Resonant Frequency (SRF):** Usually high (typically above 300–500 MHz), making it suitable for high-frequency applications. 2. **DC Resistance (DCR):** Relatively low, minimizing power loss and heat generation. 3. **Rated Current:** The maximum current it can handle before the temperature rises significantly or the inductance drops (Saturation). For this size, it usually ranges between **300mA to 600mA**. --- ### 4. Common Applications Due to its small footprint (2520 metric / 1008 imperial) and inductance value, it is frequently used in: * **RF Tuning:** Used in wireless communication modules. * **Filtering:** Decoupling and noise suppression in power lines. * **Mobile Devices:** Smartphones, tablets, and wearables where space is at a premium. * **Automotive Electronics:** Infotainment systems and sensor modules. ---