The **FSLM2520-R39J** is a surface-mount (SMD) wire-wound chip inductor commonly used in high-frequency circuits. It is part of the FSLM series manufactured by companies like TDK. --- ### 1. General Specifications The part number itself contains the primary technical characteristics: | Parameter | Specification | | :--- | :--- | | **Series** | FSLM (Wire-wound Chip Inductor) | | **Size Code** | 2520 (Metric: 2.5mm x 2.0mm / Imperial: 1008) | | **Inductance** | 0.39 µH (R39) | | **Tolerance** | ±5% (J) | | **Inductance Method** | Wire-wound around a ferrite core | --- ### 2. Electrical Characteristics Beyond basic inductance, the performance of the R39J is defined by its ability to handle current and maintain signal integrity. | Feature | Value (Approximate) | | :--- | :--- | | **Self-Resonant Frequency (SRF)** | 250 MHz (Minimum) | | **Q-Factor** | 30 (at 25.2 MHz) | | **DC Resistance (DCR)** | 0.55 $\Omega$ (Maximum) | | **Rated Current ($I_{dc}$)** | 350 mA (Maximum) | | **Operating Temperature** | -40°C to +85°C | --- ### 3. Key Features & Applications #### Features: * **High Q-Factor:** Designed for high-frequency stability. * **Wire-Wound Structure:** Provides higher current handling and lower DC resistance compared to multilayer inductors. * **Magnetic Shielding:** While compact, the wire-wound ferrite construction helps localize the magnetic field. * **Solderability:** Features tin-plated electrodes suitable for reflow soldering. #### Applications: 1. **Telecommunications:** Used in mobile phones and wireless communication modules. 2. **RF Circuits:** Ideal for matching circuits and resonance circuits in high-frequency stages. 3. **Signal Processing:** Used for noise suppression and filtering in video and audio equipment. --- ### 4. Part Number Breakdown The nomenclature follows a standard industry pattern: `FSLM` | `2520` | `-` | `R39` | `J` --- | --- | --- | --- | --- **Series Name** | **Dimensions** | | **Inductance Value** | **Tolerance** FSLM | 2.5 x 2.0 mm | | R39 = 0.39µH | J = ±5%