The **SWI0805F-R18K** is a surface-mount (SMD) wire-wound ceramic inductor. It belongs to the 0805 series of high-frequency chip inductors, commonly used in RF (Radio Frequency) and telecommunications equipment. ### 1. Part Number Breakdown Understanding the alphanumeric code helps identify the technical specifications: | Segment | Meaning | Detail | | :--- | :--- | :--- | | **SWI** | Series Prefix | Standard Wire-wound Inductor | | **0805** | Case Size | 0.08 x 0.05 inches (2.0 x 1.25 mm) | | **F** | Material / Type | Often denotes Ferrite or High-Frequency Ceramic | | **R18** | Inductance Value | R represents the decimal: **0.18 µH** (or 180 nH) | | **K** | Tolerance | **±10%** | --- ### 2. Technical Specifications The typical electrical characteristics for this specific part include: * **Inductance:** 180 nH (0.18 µH) * **Tolerance:** ±10% * **Quality Factor (Q):** Typically high (approx. 25–40 at test frequencies). * **Self-Resonant Frequency (SRF):** Usually above 600 MHz - 1 GHz. * **DC Resistance (DCR):** Low resistance to minimize power loss (typically < 1.0 Ω). * **Rated Current:** Usually ranges between 200mA and 600mA depending on the specific manufacturer (e.g., Fenghua, Taiyo Yuden). --- ### 3. Key Features * **Wire-Wound Construction:** Unlike multilayer inductors, the wire-wound design offers significantly higher Q factors and higher current handling capabilities. * **Ceramic Core:** Provides excellent thermal stability and high SRF, making it ideal for high-frequency applications. * **Compact Footprint:** The 0805 package is small enough for modern dense PCBs but large enough for easy automated assembly. --- ### 4. Common Applications Due to its high Q and frequency stability, the SWI0805F-R18K is found in: 1. **RF Circuits:** Matching networks, filters, and oscillators. 2. **Mobile Communication:** Smartphones, GPS modules, and Wi-Fi routers. 3. **Signal Conditioning:** Decoupling and EMI suppression in high-speed data lines. ---