The **CT0402LSF-R47K** is a high-performance, surface-mount (SMD) wire-wound chip inductor. This specific part is designed for high-frequency applications where stability and a high Quality (Q) factor are required. ### 1. Part Number Breakdown Understanding the alphanumeric code helps identify the component's exact specifications: | Segment | Meaning | Value / Description | | :--- | :--- | :--- | | **CT** | Series Identifier | Wire-wound Chip Inductor | | **0402** | Case Size | 0.4mm x 0.2mm (EIA 0402) | | **LSF** | Product Type | Low Profile / High Frequency Ferrite Core | | **R47** | Inductance Value | 0.47 µH (470 nH) | | **K** | Tolerance | ±10% | --- ### 2. Technical Specifications The electrical characteristics of this component are critical for circuit design, particularly in RF and power management stages. | Parameter | Specification | | :--- | :--- | | **Inductance** | 0.47 µH | | **Tolerance** | ±10% | | **Self-Resonant Frequency (SRF)** | Typically > 500 MHz | | **DC Resistance (DCR)** | Low (approx. 0.5 - 1.2 Ohms max) | | **Rated Current** | Typically 150mA to 300mA | | **Operating Temperature** | -40°C to +125°C | --- ### 3. Key Physical Features * **Construction:** Wire-wound technology over a ceramic or ferrite core. Wire-wound inductors generally offer much higher Q factors and lower DCR than multilayer alternatives. * **Size:** The **0402** footprint is extremely small (roughly the size of a grain of salt), making it ideal for compact mobile devices. * **Termination:** Usually features gold or tin plating for excellent solderability and resistance to "leaching" during the reflow process. --- ### 4. Common Applications Due to its small size and stable inductance, the CT0402LSF-R47K is typically found in: 1. **RF Circuits:** Matching networks for Bluetooth, Wi-Fi, and cellular antennas. 2. **Filter Networks:** Low-pass or band-pass filters in high-frequency signal paths. 3. **Decoupling:** Filtering high-frequency noise in power supply lines for sensitive ICs. 4. **Mobile Electronics:** Smartphones, wearables, and IoT sensors where PCB real estate is limited. --- ### 5. Schematic Symbol & Footprint ```text Symbol: ---( L )--- (Inductor) PCB Footprint (0402): [ Pad ] 0.5mm [ Pad ] <------- 1.0mm -------> ```