The **0603CS-R21XL** is a specific part number for a surface-mount (SMD) wire-wound ceramic core chip inductor. It is commonly manufactured by companies like **Coilcraft**. Below is a detailed breakdown of its specifications and electronic characteristics. ### 1. Part Number Breakdown Understanding the nomenclature helps identify the physical and electrical constraints: | Segment | Meaning | Description | | :--- | :--- | :--- | | **0603** | Package Size | Imperial code (1.6mm x 0.8mm) | | **CS** | Series Type | Ceramic core, standard tolerance | | **R21** | Inductance Value | **210 nH** (R denotes decimal: 0.21 µH) | | **X** | Tolerance | Typically ±5% (standard for this series) | | **L** | Termination/Finish | Usually denotes Lead-free / RoHS compliant (Matte tin over platinum/glass frit) | --- ### 2. Key Electrical Specifications The "CS" series is known for high **Q-factors** and high self-resonant frequencies (SRF), making them ideal for high-frequency RF applications. | Parameter | Value (Typical) | | :--- | :--- | | **Inductance** | 210 nH | | **Tolerance** | ±5% | | **Quality Factor (Q) min** | 28 at 100 MHz | | **Self-Resonant Frequency (SRF)** | 900 MHz (min) | | **DC Resistance (DCR) max** | 1.30 Ohms | | **Current Rating (IDC)** | 240 mA | --- ### 3. Core Material & Construction * **Ceramic Core:** Unlike ferrite cores, ceramic cores do not store significant magnetic energy. This results in **zero magnetic saturation**, meaning the inductance remains constant regardless of the current passing through it (within thermal limits). * **Wire-Wound:** The inductor consists of a copper wire wrapped around a ceramic body. This construction provides much lower DCR and higher Q-factors compared to multilayer ceramic inductors. --- ### 4. Applications Due to its high frequency stability and high SRF, the 0603CS-R21XL is typically used in: * **RF Tuning Circuits:** Impedance matching for antennas. * **Filter Networks:** Band-pass or high-pass filters in wireless communication. * **VCOs:** Voltage Controlled Oscillators. * **Broadband Isolation:** Preventing RF noise from entering DC power lines in high-frequency modules. --- ### 5. Physical Dimensions | Dimension | Millimeters (mm) | | :--- | :--- | | **Length** | 1.60 - 1.80 | | **Width** | 0.80 - 1.12 | | **Height** | 0.80 - 1.10 |