The **1812SMS-R12GLC** is a high-performance Surface Mount (SMD) Air Core Inductor manufactured by **Coilcraft**. These components are specifically designed for high-frequency applications where high "Q" (Quality Factor) and high current handling are required. --- ### 1. Key Technical Specifications | Parameter | Value / Description | | :--- | :--- | | **Inductance** | 120 nH (Nanohenries) | | **Tolerance** | ±2% (indicated by the 'G' in the part number) | | **Package Size** | 1812 (4.57 mm x 3.81 mm) | | **Core Material** | Air Core (Non-magnetic) | | **Frequency (Min SRF)** | 1.1 GHz (Self-Resonant Frequency) | | **DCR (Max)** | 0.046 Ohms | | **Irms (Max Current)** | 4.0 Amps | | **Termination** | Leaded (Solder coated) | --- ### 2. Part Number Breakdown Understanding the nomenclature helps in identifying variants: * **1812**: The physical dimensions (0.18 x 0.12 inches). * **SMS**: Series designation (Surface Mount Spring inductor). * **R12**: The inductance value ($0.12 \mu H$ or $120 nH$). * **G**: Tolerance code ($\pm 2\%$). * **L**: Termination style (often refers to RoHS compliant / Tin-Silver-Copper). * **C**: Packaging code (usually refers to 7-inch machine-ready reel). --- ### 3. Features and Benefits * **High Q Factor:** Because it uses an air core rather than a ferrite core, it lacks core losses, resulting in exceptionally high Q factors at high frequencies. * **High Current Handling:** Capable of carrying up to 4.0 Amps, which is significantly higher than standard chip inductors of similar size. * **Flat Top Cap:** Features a heat-resistant cap on top of the coil to allow for automated "pick and place" assembly and to protect the windings. * **Temperature Stability:** Air core inductors offer excellent inductance stability across a wide temperature range compared to magnetic core alternatives. --- ### 4. Common Applications Due to its high frequency and high current characteristics, it is typically found in: 1. **RF Power Amplifiers:** For impedance matching and DC biasing. 2. **Filter Networks:** Used in high-pass, low-pass, and band-pass filters for telecommunications. 3. **Antenna Matching:** Optimizing signal transfer in wireless devices. 4. **MRI Equipment:** Applications requiring non-magnetic components. ---