The **2SA1941-R** is a high-power PNP epitaxial silicon transistor primarily designed for high-fidelity (Hi-Fi) audio power amplification. It is frequently paired with its NPN complement, the **2SC5198**, in push-pull output stages. --- ### 1. Key Technical Specifications The "R" suffix typically denotes the **hFE (current gain)** classification, usually ranging from 55 to 110. | Parameter | Symbol | Rating | Unit | | :--- | :--- | :--- | :--- | | Collector-Base Voltage | $V_{CBO}$ | -140 | V | | Collector-Emitter Voltage | $V_{CEO}$ | -140 | V | | Emitter-Base Voltage | $V_{EBO}$ | -5 | V | | Collector Current (DC) | $I_C$ | -10 | A | | Collector Power Dissipation | $P_C$ | 100 | W | | Junction Temperature | $T_j$ | 150 | °C | --- ### 2. Physical and Pin Configuration The device is housed in a **TO-3P** (or TO-247) package, which is designed for easy mounting to heat sinks to manage the 100W power dissipation. | Pin Number | Name | Function | | :--- | :--- | :--- | | 1 | **Base** | Controls the current flow between collector and emitter | | 2 | **Collector** | Connected to the negative supply in PNP configurations | | 3 | **Emitter** | The output terminal (usually connected to the load) | --- ### 3. Core Features * **High Power Handling:** Capable of handling up to 100W, making it suitable for 60W–100W audio amplifiers. * **Excellent Linearity:** It provides low harmonic distortion, which is critical for high-quality audio reproduction. * **High Voltage Rating:** With a 140V breakdown voltage, it is safe for use in high-voltage rail power supplies. * **Complementary Pairing:** Works seamlessly with the **2SC5198** NPN transistor for symmetrical waveform amplification. --- ### 4. Typical Applications 1. **Audio Output Stage:** Used as the power output transistor in home stereo receivers and professional amplifiers. 2. **Power Regulators:** Utilized in high-current linear power supply circuits. 3. **General Purpose Switching:** Can be used in industrial high-power switching applications, though it is optimized for audio. --- ### 5. Example Schematic Concept (Output Pair) ```text +Vcc (Positive Rail) | [2SC5198] (NPN) |------- Speaker Output [2SA1941] (PNP) | -Vee (Negative Rail) ```