### Technical Overview: 2SD1663 Transistor The **2SD1663** is an NPN epitaxial planar silicon transistor. It is primarily designed for high-voltage switching applications, specifically horizontal deflection output in high-resolution displays and color televisions. --- ### 1. Key Features * **High Speed:** Optimized for rapid switching cycles. * **High Breakdown Voltage:** Capable of handling significant voltage spikes typical in inductive loads. * **Low Saturation Voltage:** Ensures efficiency and reduces heat dissipation during operation. --- ### 2. Technical Specifications Below are the absolute maximum ratings and electrical characteristics (at $T_a = 25^\circ C$ unless otherwise specified): | Parameter | Symbol | Rating | Unit | | :--- | :--- | :--- | :--- | | Collector-Base Voltage | $V_{CBO}$ | 1500 | V | | Collector-Emitter Voltage | $V_{CEO}$ | 800 | V | | Emitter-Base Voltage | $V_{EBO}$ | 6 | V | | Collector Current (DC) | $I_C$ | 5 | A | | Collector Current (Pulse) | $I_{CP}$ | 10 | A | | Collector Power Dissipation | $P_C$ | 50 | W | | Junction Temperature | $T_j$ | 150 | $^\circ C$ | --- ### 3. Pin Configuration The 2SD1663 is usually found in a **TO-3PFM** or similar isolated power package. Looking at the front (labeled side) with leads pointing down: 1. **Base (B):** The trigger for the transistor. 2. **Collector (C):** Connected to the load (usually the center pin). 3. **Emitter (E):** Usually connected to ground or the negative rail. --- ### 4. Common Applications Due to its high voltage rating, it is commonly used in: * **CRT Monitors:** Horizontal deflection output stages. * **Power Supplies:** High-voltage switching regulators. * **Inverters:** DC-AC conversion circuits. --- ### 5. Equivalent/Replacement Parts If the 2SD1663 is unavailable, the following parts may serve as functional substitutes (always check the datasheet for package compatibility): * **2SD1877** * **KSD1663** * **BU2508AF** ---