### CW201212-R91J Overview The **CW201212-R91J** is a high-frequency, wire-wound chip inductor commonly used in RF (Radio Frequency) communication circuits. It is manufactured by companies like **Bourns** and follows industry-standard sizing and performance metrics. --- ### Technical Specifications The part number itself acts as a code for its primary characteristics. Below is a detailed breakdown of its electronic properties: | Parameter | Specification | Details | | :--- | :--- | :--- | | **Inductance** | 910 nH (0.91 µH) | The "R91" indicates 0.91. | | **Tolerance** | ±5% | Indicated by the suffix "J". | | **Package Size** | 0805 (Metric 2012) | 2.0mm x 1.25mm. | | **Material Core** | Ceramic | Non-magnetic core for high-frequency stability. | | **DC Resistance (DCR)** | ~1.60 Ohms (Max) | Resistance to direct current. | | **Rated Current** | ~200 mA | Maximum continuous current allowable. | | **Self-Resonant Freq.** | ~380 MHz | The point where the part becomes capacitive. | | **Quality Factor (Q)** | 25 (Min) | Efficiency at a specific frequency (usually 50MHz). | --- ### Part Number Breakdown Understanding the nomenclature helps in identifying similar components: 1. **CW**: Chip Wire-wound. 2. **2012**: Dimensions in millimeters (2.0mm x 1.2mm). 3. **12**: Height profile (approx. 1.2mm). 4. **R91**: Inductance value ($R$ acts as a decimal point, measured in $\mu H$). 5. **J**: Tolerance code ($J = 5\%$, $K = 10\%$, $M = 20\%$). --- ### Key Applications Due to its ceramic core and wire-wound construction, this component is ideal for: * **RF Matching Networks:** Ensuring impedance matching between antennas and transceivers. * **Filters:** Used in Low-Pass or Band-Pass filters for signal processing. * **High-Frequency Oscillators:** Maintaining stable resonance in wireless devices. * **Mobile Communication:** Found in GPS, Bluetooth, and Wi-Fi modules. --- ### Comparison: Ceramic vs. Ferrite Core It is important to note that the `CW201212` series typically utilizes a **Ceramic core**. ```markdown - Ceramic Core: High Q, high self-resonant frequency, low inductance values. - Ferrite Core: Lower Q, lower self-resonant frequency, but much higher inductance density. ```