## Technical Overview: CW201212-R15J The **CW201212-R15J** is a high-frequency, wire-wound chip inductor commonly manufactured by Bourns. It is designed for RF circuits where high stability and a high Quality (Q) factor are required. --- ### 1. Key Technical Specifications | Parameter | Specification | Details | | :--- | :--- | :--- | | **Inductance** | 150 nH | Measured at 100 MHz | | **Tolerance** | ±5% (J) | "J" indicates a 5% deviation range | | **Case Size** | 0805 (Metric 2012) | 2.0 mm x 1.25 mm footprint | | **Max DC Current** | 400 mA | The maximum continuous current allowed | | **DC Resistance (DCR)** | 0.56 Ω Max | Resistance of the internal copper wire | | **SRF (Self-Resonant Freq)** | 1100 MHz | Frequency where it acts as a capacitor | | **Q Factor (Minimum)** | 60 | Measured at 500 MHz | --- ### 2. Part Number Breakdown The part number follows a specific nomenclature used by manufacturers: * **CW**: Chip Wire-wound (Indicates the construction style). * **201212**: Physical dimensions ($L \times W \times H$) in millimeters (2.0 x 1.2 x 1.2 mm). This corresponds to the **0805** EIA size. * **R15**: Represents the inductance value. The "R" acts as a decimal point. **R15 = 0.15 µH = 150 nH**. * **J**: Indicates the tolerance code. **J = ±5%**. --- ### 3. Construction and Features 1. **Wire-wound Core**: Unlike multilayer inductors, these use a copper wire wound around a ceramic or ferrite core. This results in much lower DC resistance and a higher Q factor. 2. **Ceramic Body**: Typically utilizes an alumina ceramic body which provides excellent mechanical strength and stable performance across temperature shifts. 3. **Epoxy Coating**: The top is usually coated with a clear epoxy or resin to allow for vacuum pick-and-place assembly during manufacturing. --- ### 4. Common Applications Due to its high frequency capabilities and precise tolerance, the CW201212-R15J is found in: * **RF Communication**: Cellular phones, GPS receivers, and Wi-Fi modules. * **Impedance Matching**: Matching circuits for antennas to ensure maximum power transfer. * **Filtering**: Used in band-pass or high-pass filters to remove unwanted noise in high-speed signal lines.