The **CTLL2012-R39J** is a surface-mount (SMD) wire-wound chip inductor commonly used in high-frequency circuits. It is part of the CTLL series, typically manufactured by companies like Central Technologies. --- ### 1. Part Number Breakdown Understanding the alphanumeric code helps identify the component's core specifications: | Segment | Meaning | Value | | :--- | :--- | :--- | | **CTLL** | Series Series | Low Loss / High Q Inductor | | **2012** | Package Size | 2.0mm x 1.25mm (EIA 0805) | | **R39** | Inductance Value | 0.39 µH (390 nH) | | **J** | Tolerance | ±5% | --- ### 2. Technical Specifications Below are the typical electrical characteristics for this specific part: | Parameter | Value | | :--- | :--- | | **Inductance** | 0.39 µH | | **Tolerance** | ±5% | | **Test Frequency** | 25 MHz | | **Quality Factor (Q) Min** | 25 | | **Self-Resonant Frequency (SRF)** | ~250 MHz | | **DC Resistance (DCR) Max** | 0.45 Ω | | **Rated Current (I-rms)** | ~450 mA | | **Operating Temperature** | -40°C to +125°C | --- ### 3. Key Electronic Features * **Wire-Wound Construction:** Unlike multilayer inductors, wire-wound versions offer much higher **Q factors** and lower DC resistance, making them more efficient for power and RF applications. * **Ceramic Core:** Usually built on a ceramic body which provides excellent thermal stability and high self-resonant frequencies. * **Small Footprint:** The 0805 (2012 metric) size is a standard for compact PCB designs, balancing ease of assembly with space-saving. --- ### 4. Common Applications Due to its high Q and moderate inductance, the CTLL2012-R39J is frequently found in: 1. **RF Circuits:** Matching networks and filters in wireless communication devices. 2. **High-Speed Signal Lines:** To suppress electromagnetic interference (EMI) without degrading signal integrity. 3. **Local Oscillators:** Providing stable inductance for frequency generation. 4. **Mobile Electronics:** Power management modules where low DCR is required to maintain battery life. ---