The part number **SMDCHR0805-R18** refers to a Surface Mount Device (SMD) power inductor, typically used in high-frequency power management circuits. --- ### 1. Part Number Breakdown The nomenclature follows industry standards for passive components: | Segment | Meaning | Description | | :--- | :--- | :--- | | **SMD** | Surface Mount Device | Designed for automated PCB assembly. | | **CH** | Chip Inductor / High Current | Often denotes a ceramic or high-frequency wire-wound series. | | **R** | RoHS / Series Indicator | Sometimes indicates compliance or a specific manufacturer series. | | **0805** | Case Size (Imperial) | Dimensions: **2.0mm x 1.25mm** (length x width). | | **R18** | Inductance Value | **0.18 µH** (The 'R' acts as a decimal point). | --- ### 2. Technical Specifications While exact specifications can vary by manufacturer (e.g., Bourns, TDK, or Murata), a standard **0805 0.18µH inductor** generally falls within these parameters: * **Inductance:** 0.18 µH (180 nH). * **Tolerance:** Typically ±10% or ±20%. * **DC Resistance (DCR):** Usually very low (mΩ range) to minimize power loss. * **Rated Current (Iat):** Generally ranges from **300mA to 800mA**, depending on whether it is a wire-wound or multilayer type. * **Self-Resonant Frequency (SRF):** High, often above 500 MHz, making it suitable for RF applications. --- ### 3. Key Features * **Small Footprint:** The 0805 package is ideal for compact consumer electronics like smartphones and tablets. * **Low DCR:** Efficient for battery-powered devices. * **Magnetic Shielding:** Many "CH" series inductors are shielded to prevent Electromagnetic Interference (EMI) with neighboring components. --- ### 4. Common Applications These parts are typically found in: 1. **DC-DC Converters:** Used for voltage regulation in low-power circuits. 2. **RF Circuits:** Used for impedance matching and signal filtering in wireless communication. 3. **EMI Suppression:** Acting as a high-frequency choke to filter noise out of power lines.