Based on the model number provided, the **SWC85I-R39KA** typically refers to a specialized **Wireless Charging Coil** or an integrated module used in inductive power transfer systems. These components are essential for Qi-standard or proprietary wireless charging applications. Below is a breakdown of the electronic characteristics and technical components of this part. --- ### 1. Component Overview The SWC85I-R39KA is a high-efficiency wireless power charging coil, often featuring a ferrite plate for magnetic shielding and flux concentration. | Feature | Specification (Typical) | | :--- | :--- | | **Component Type** | Inductive Charging Coil / Receiver or Transmitter | | **Inductance** | ~3.9 µH (indicated by "39K" in suffix) | | **Material** | Litz Wire (multi-strand) + Ferrite Shield | | **Mounting Type** | Surface Mount or Lead Wire (depending on housing) | | **Standard Compliance** | Qi Wireless Power Consortium (WPC) | --- ### 2. Key Electronic Parts & Construction The assembly consists of three primary electronic elements: #### A. The Induction Coil * **Material:** Usually constructed from **Litz wire**, which consists of many thin wire strands individually insulated and twisted together. This reduces the **Skin Effect**, minimizing AC resistance at high frequencies (typically 100–200 kHz). * **Function:** Converts the oscillating magnetic field from the transmitter into an AC electrical current (or vice versa). #### B. Ferrite Shielding (Magnetic Sheet) * **Material:** Sintered Ferrite or Flexible Magnetic Sheet. * **Function:** 1. **Flux Concentration:** Directs the magnetic field toward the opposing coil to improve coupling efficiency. 2. **EMI Protection:** Prevents the magnetic field from interfering with the internal electronics of the device (battery, PCB, etc.) and reduces eddy currents in nearby metal parts. #### C. Adhesive and Terminals * **Adhesive:** High-temperature resistant pressure-sensitive adhesive (PSA) used to mount the coil to the device chassis. * **Terminals:** Pre-tinned leads for soldering directly to a Wireless Power Receiver (Rx) or Transmitter (Tx) IC circuit. --- ### 3. Electrical Characteristics The "R39KA" suffix provides specific clues about its electrical behavior: * **R39:** Represents the nominal inductance value (3.9 microhenries). * **K:** Usually denotes a tolerance of ±10%. * **Q-Factor:** These coils are designed for a high **Quality Factor (Q)** to ensure maximum power transfer efficiency and minimal heat dissipation. --- ### 4. Typical Application Circuit When integrated into a system, this part works alongside the following components: ```mermaid graph LR A[Transmitter Coil] -- Magnetic Flux --> B(SWC85I-R39KA Coil) B --> C[Resonant Capacitors] C --> D[Bridge Rectifier] D --> E[DC-DC Regulator] E --> F[Battery Charging IC] ```