The **81N50L-R-AB3-I-R** is a high-voltage N-Channel Power MOSFET manufactured by UTC (Unisonic Technologies). It is designed for high-efficiency switching applications, such as power supplies and motor controllers. --- ### 1. Key Technical Specifications The part number follows a specific nomenclature that defines its electrical characteristics and physical packaging. | Parameter | Value / Description | | :--- | :--- | | **Transistor Type** | N-Channel MOSFET | | **Drain-Source Voltage ($V_{DSS}$)** | 500V | | **Continuous Drain Current ($I_D$)** | 8.0A | | **Pulsed Drain Current ($I_{DM}$)** | 32A | | **Gate-Source Voltage ($V_{GSS}$)** | $\pm$ 30V | | **On-Resistance ($R_{DS(ON)}$)** | Approx. 0.85 $\Omega$ (Max @ $V_{GS}=10V$) | | **Package Type** | SOT-89 (High power density surface mount) | --- ### 2. Breakdown of the Part Number UTC uses a coding system to identify specific features of the component: * **81N50**: Represents the basic model (8A current rating, 500V voltage rating). * **L**: Lead-free / RoHS compliant. * **R**: Taping (Reel) packaging. * **AB3**: Refers to the **SOT-89** package style. * **I**: Specific internal classification or improved characteristic (often related to gate charge or thermal performance). * **R**: Halogen-free material. --- ### 3. Application Areas Due to its high voltage rating and relatively low on-resistance, this MOSFET is commonly found in: 1. **Switching Mode Power Supplies (SMPS):** Used as the primary switch in AC-DC converters. 2. **LED Lighting Drivers:** Provides reliable switching for high-voltage LED arrays. 3. **DC-DC Converters:** Efficient power conversion in industrial electronics. 4. **Motor Control:** Small motor drives requiring high-voltage handling. --- ### 4. Typical Circuit Symbol & Pinout The SOT-89 package generally follows this standard pin configuration for MOSFETs: ```text Pin 1: Gate (G) - Controls the turning ON/OFF of the MOSFET. Pin 2: Drain (D) - The output terminal (connected to the load). Pin 3: Source (S) - The common terminal (usually connected to ground). ``` ---