## 2SC4688-R: NPN Epitaxial Silicon Transistor The **2SC4688-R** is a high-power NPN epitaxial silicon transistor primarily designed for high-power audio amplification and general-purpose switching applications. It is often paired with its PNP complement, the **2SA1803**. --- ### 1. Key Technical Specifications The following table summarizes the absolute maximum ratings and electrical characteristics for the 2SC4688 (R-variant). | Parameter | Symbol | Rating | Unit | | :--- | :--- | :--- | :--- | | Collector-Base Voltage | $V_{CBO}$ | 230 | V | | Collector-Emitter Voltage | $V_{CEO}$ | 230 | V | | Emitter-Base Voltage | $V_{EBO}$ | 5 | V | | Collector Current (DC) | $I_C$ | 15 | A | | Collector Power Dissipation | $P_C$ | 150 | W | | Junction Temperature | $T_j$ | 150 | °C | | Current Gain Group (R) | $h_{FE}$ | 55 to 110 | - | --- ### 2. Physical Characteristics The 2SC4688 is typically housed in a **TO-3P** or **TO-264** package, designed for high heat dissipation. * **Pinout Configuration:** 1. **Base (B):** Control terminal. 2. **Collector (C):** Connected to the metal tab/heatsink. 3. **Emitter (E):** Output/Return path. --- ### 3. Application Areas Due to its high voltage and current handling capabilities, it is used in: * **High-Fidelity Audio:** Output stages of professional power amplifiers. * **Power Supplies:** Linear regulators and DC-DC converters. * **Industrial Control:** High-current switching for motors or solenoids. ### 4. Meaning of the "R" Suffix In Japanese transistor nomenclature (JIS), the trailing letter usually refers to the **hFE (DC Current Gain)** classification: * **O (Orange):** 45 – 90 * **R (Red):** 55 – 110 * **Y (Yellow):** 80 – 160 --- ### 5. Equivalent/Replacement Parts If the 2SC4688-R is unavailable, the following components are often used as functional substitutes (verify pinouts and ratings before use): ```text 1. 2SC5200 (Commonly used in audio) 2. 2SC3281 3. TIP35C (General purpose, lower voltage) 4. MJL21194 ```