The **2SC4635LS** is a NPN epitaxial silicon transistor designed primarily for high-definition color display horizontal deflection output and high-speed switching applications. It is manufactured by Sanyo (now part of ON Semiconductor). --- ## 1. Key Technical Specifications The following table summarizes the absolute maximum ratings and electrical characteristics of the 2SC4635LS. | Parameter | Symbol | Rating / Value | Unit | | :--- | :--- | :--- | :--- | | **Collector-to-Base Voltage** | $V_{CBO}$ | 1500 | V | | **Collector-to-Emitter Voltage** | $V_{CEO}$ | 800 | V | | **Emitter-to-Base Voltage** | $V_{EBO}$ | 6 | V | | **Collector Current (DC)** | $I_C$ | 2.5 | A | | **Collector Current (Pulse)** | $I_{CP}$ | 5 | A | | **Collector Dissipation** | $P_C$ | 2.0 ($Tc=25^\circ C$) | W | | **Junction Temperature** | $T_j$ | 150 | $^\circ C$ | | **Storage Temperature** | $T_{stg}$ | -55 to +150 | $^\circ C$ | --- ## 2. Features and Package - **High Speed:** It features a very short fall time, making it efficient for switching circuits. - **High Reliability:** Designed to withstand high breakdown voltages (1500V). - **Package Type:** It typically comes in a **TO-220FI (Full Isolation)** package. This means the metal tab is covered in plastic, allowing it to be mounted to a heatsink without an additional insulating mica sheet. ### Pin Configuration Looking at the front of the transistor (labels facing you), the pins are typically: 1. **Base (B)** 2. **Collector (C)** 3. **Emitter (E)** --- ## 3. Common Applications The 2SC4635LS is specialized for high-voltage environments. Common use cases include: 1. **Horizontal Deflection Output:** Used in CRT (Cathode Ray Tube) monitors and televisions to control the electron beam sweep. 2. **Switching Power Supplies (SMPS):** Acting as the main switching element in high-voltage power converters. 3. **High-Voltage Inverters:** Used in industrial circuits requiring fast switching at several hundred volts. --- ## 4. Equivalent / Replacement Parts If the 2SC4635LS is unavailable, the following parts are often considered as functional equivalents, though always verify the pinout and voltage ratings for your specific circuit: - **2SC4430** - **BUH315** - **KSC5027**