The **SCI1008S-R18KF** is a high-frequency, surface-mount (SMD) wire-wound ceramic core chip inductor. It is commonly used in RF (Radio Frequency) communication circuits where high stability and high Q-factors are required. ### 1. Part Number Breakdown Understanding the alphanumeric code helps identify the component's specific characteristics: | Code Segment | Meaning | Value / Description | | :--- | :--- | :--- | | **SCI** | Series Prefix | Signal Chip Inductor (Wire-wound) | | **1008** | Case Size | 1008 Imperial (approx. 2.5 x 2.0 mm) | | **S** | Termination | Standard (usually Silver/Palladium/Glass Frits) | | **R18** | Inductance Value | 0.18 µH (or 180 nH) | | **K** | Tolerance | ±10% | | **F** | Features | Lead-Free / RoHS Compliant | --- ### 2. Key Technical Specifications Below are the typical electrical parameters for this class of component: * **Inductance:** 180 nH (nanohenries). * **Tolerance:** ±10%. * **Quality Factor (Q min):** Typically 45–50 at a test frequency of 50 MHz. * **Self-Resonant Frequency (SRF):** Approximately 900 MHz to 1.2 GHz (minimum). * **DC Resistance (DCR max):** 0.50 – 0.70 Ohms. * **Rated Current:** ~500 mA (milliamps). * **Operating Temperature:** -40°C to +125°C. --- ### 3. Construction and Materials The "S" in the series often refers to the **Ceramic Core** construction: 1. **Core:** Non-magnetic ceramic body providing excellent thermal stability and a high SRF. 2. **Wire:** Fine copper wire wound around the ceramic core. 3. **Encapsulation:** Often coated with a clear epoxy resin to protect the windings and provide a flat surface for pick-and-place machines. --- ### 4. Common Applications Due to its high Q-factor and high-frequency performance, the SCI1008S-R18KF is typically found in: * **RF Filters:** Bandpass and Lowpass filters in wireless devices. * **Impedance Matching:** Matching circuits for antennas in Wi-Fi or Bluetooth modules. * **Oscillators:** Frequency determining elements in VCOs (Voltage Controlled Oscillators). * **Decoupling:** Filtering high-frequency noise in power supply lines for sensitive RF ICs. ---