The **1812SMS-R10GLC** 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-factors and tight tolerances are required. --- ### 1. Technical Specifications The part number itself follows a specific nomenclature that defines its characteristics: | Property | Value / Detail | | :--- | :--- | | **Inductance** | 100 nH (indicated by `R10`) | | **Tolerance** | ±2% (indicated by `G`) | | **Package Size** | 1812 (4.5 x 3.2 mm) | | **Core Type** | Air Core (provides high Q and no saturation) | | **Q Factor (Min)** | 100 at 150 MHz | | **Self Resonant Frequency (SRF)** | 1.1 GHz (Min) | | **DC Resistance (DCR)** | 0.56 Ohms (Max) | | **Current Rating (Irms)** | 600 mA | --- ### 2. Physical Construction * **Air Core Inductor:** Unlike inductors with ferrite or iron cores, air core inductors have a core of "air" (usually just the coil shape held by a jacket). * **Advantages:** * **No Magnetic Saturation:** The inductance remains constant regardless of the current applied. * **Low Losses:** Ideal for high-frequency RF circuits because there are no core losses (hysteresis). * **Termination:** Features tinned copper terminations for reliable soldering (RoHS compliant). --- ### 3. Application Use-Cases Because of the **100 nH** value and the **high Q factor**, this part is commonly found in: 1. **RF Impedance Matching:** Used in the output stages of power amplifiers to match the antenna impedance. 2. **Filter Networks:** Perfect for high-pass, low-pass, or band-pass filters in wireless communication devices. 3. **Tuning Circuits:** The 2% tolerance makes it suitable for precise oscillator tuning. 4. **Telecommunications:** Used in cellular infrastructure, GPS receivers, and Wi-Fi modules. --- ### 4. Part Number Breakdown `1812` `SMS` `-` `R10` `G` `L` `C` * **1812:** EIA Package size (0.18 x 0.12 inches). * **SMS:** Series identifier (Surface Mount, Spring/Air core). * **R10:** Inductance value (R is the decimal; R10 = 0.10 µH or 100 nH). * **G:** Tolerance code (G = ±2%; J = ±5%). * **L:** Termination style (L = RoHS compliant Silver-Palladium-Platinum-Glass frit). * **C:** Packaging (C = 7" Machine Ready Reel).