The **CW201212-R39J** is a high-frequency, wire-wound chip inductor commonly used in RF (Radio Frequency) circuits. It is part of the CW series manufactured by companies like Bourns. Below is a detailed breakdown of its specifications and characteristics. --- ### 1. Technical Specifications The part number follows a standardized naming convention that describes its physical and electrical properties. | Parameter | Value | Description | | :--- | :--- | :--- | | **Inductance** | 390 nH | (R39 = 0.39 µH or 390 nanohenries) | | **Tolerance** | ±5% | Indicated by the suffix 'J' | | **Package Size** | 0805 (Metric 2012) | 2.0mm x 1.25mm footprint | | **Core Material** | Ceramic | Non-magnetic core for high-frequency stability | | **SRF (Min)** | 500 MHz | Self-Resonant Frequency | | **Q Factor (Min)** | 25 | Measured at 100 MHz | | **DC Resistance** | 1.12 Ω (Max) | Resistance of the copper wire | | **Rated Current** | 200 mA | Maximum continuous current | --- ### 2. Part Number Breakdown Understanding the nomenclature helps in identifying similar components: * **CW**: Series name (Wire-wound Chip Inductor). * **2012**: Physical dimensions ($2.0 \times 1.2$ mm). * **12**: Height profile (approx. 1.2 mm). * **R39**: Inductance value ($R$ acts as decimal; $0.39$ µH). * **J**: Tolerance code ($J = \pm5\%$, $K = \pm10\%$, $G = \pm2\%$). --- ### 3. Key Features and Applications #### Key Features * **High Q Factor:** The wire-wound construction provides significantly lower DC resistance and higher Q (Quality) factors compared to multilayer inductors. * **High Resonance:** The ceramic core allows the part to operate at very high frequencies without significant core losses. * **Small Footprint:** The 0805 size is ideal for compact PCB designs. #### Common Applications 1. **RF Matching Networks:** Tuning circuits in antennas for Wi-Fi, Bluetooth, and cellular modules. 2. **Filters:** Used in Band-pass or High-pass filters to eliminate noise. 3. **VCOs:** Voltage-controlled oscillators in telecommunication equipment. 4. **Signal Conditioning:** High-speed data lines requiring impedance matching. --- ### 4. Typical Footprint (Dimensions) ```text L: 2.0mm [0.079"] W: 1.2mm [0.047"] H: 1.2mm [0.047"] _________________ | Top View | | [Inductor] | |_________________| ```