The **2SA1483-R** is a high-frequency, PNP epitaxial silicon transistor primarily designed for audio frequency (AF) amplifiers and high-speed switching applications. It is commonly found in surface-mount configurations, making it suitable for compact electronic assemblies. --- ### ## 1. Key Technical Specifications The "R" suffix typically denotes the **hfe (DC current gain)** classification, which falls within a specific range defined by the manufacturer. | Parameter | Symbol | Maximum Rating | | :--- | :--- | :--- | | **Collector-Base Voltage** | $V_{CBO}$ | -30 V | | **Collector-Emitter Voltage** | $V_{CEO}$ | -25 V | | **Emitter-Base Voltage** | $V_{EBO}$ | -5 V | | **Collector Current (DC)** | $I_C$ | -500 mA | | **Collector Power Dissipation** | $P_C$ | 200 - 300 mW | | **Junction Temperature** | $T_j$ | 150 °C | | **Current Gain Bandwidth** | $f_T$ | 200 MHz (Typical) | --- ### ## 2. Pin Configuration The 2SA1483 is usually packaged in an **SOT-23** (Small Outline Transistor) format. 1. **Base (B):** Controls the flow of current between Emitter and Collector. 2. **Emitter (E):** The source of charge carriers (holes for PNP). 3. **Collector (C):** The output terminal. --- ### ## 3. Main Features * **High Current Capacity:** Despite its small size, it can handle a continuous collector current of up to 500mA. * **Complementary Pair:** It is often paired with the **2SC3803** (NPN version) for push-pull amplifier circuits. * **High-Speed Switching:** Low capacitance and high $f_T$ make it efficient for fast switching cycles. * **Low Saturation Voltage:** Ensures minimal power loss when the transistor is fully "ON." --- ### ## 4. Common Applications * **Audio Preamplifiers:** Used in the initial stages of sound processing for low-noise amplification. * **Driver Circuits:** Acting as a switch or driver for small motors, LEDs, or relays. * **Voltage Regulation:** Part of low-power linear voltage regulator circuits. * **Signal Processing:** High-frequency signal switching in telecommunication devices. --- ### ## 5. Design Example (Switching) In a simple PNP switching circuit, the load is connected between the Collector and Ground (or a negative rail). ```markdown Circuit Logic: 1. Logic LOW (0V) at Base -> Transistor ON (Current flows). 2. Logic HIGH (Vcc) at Base -> Transistor OFF (Current stops). ``` ---