The **2SA** prefix refers to a specific naming convention under the **Japanese Industrial Standards (JIS)** for semiconductor devices. Specifically, "2SA" identifies a **PNP High-Frequency Transistor**. The **"-R"** suffix typically refers to a specific **Gain Classification (hFE)** or, in some contexts, the packaging style (e.g., Taping/Reel). --- ### 1. Decoding the Part Number: 2SAXXXX The Japanese naming system follows a specific logic: | Part Segment | Meaning | Details | | :--- | :--- | :--- | | **2** | Number of Junctions | Indicates a 3-terminal device (Transistor). | | **S** | Registered with EIAJ | Standard Japanese registration. | | **A** | Device Type | **PNP** High-Frequency (AF/RF) Transistor. | | **XXXX** | Serial Number | The specific model ID (e.g., 2SA1015). | | **-R** | Suffix | Usually denotes the **Current Gain (hFE)** range. | --- ### 2. Common "R" Gain Classifications In many Japanese transistors (like the 2SA1015, 2SA933, or 2SA733), the letter "R" identifies the specific Beta/Gain range of that batch. | Suffix | Typical hFE (Gain) Range | | :--- | :--- | | **O** | 70 – 140 | | **Y** | 120 – 240 | | **G** | 200 – 400 | | **L** | 350 – 700 | | **R** | Usually implies a specific range (often 40-80 or 180-390 depending on manufacturer). | --- ### 3. Technical Characteristics of 2SA Transistors Because "2SA" designates PNP high-frequency parts, they generally share these traits: * **Polarity:** PNP (Current flows from Emitter to Collector when the Base is pulled low). * **Application:** Used in voltage amplification, high-speed switching, and RF oscillators. * **Complementary Pair:** They are often paired with **2SC** (NPN) transistors for push-pull amplifier circuits. ### 4. Example: 2SA1015-R If you are looking at a **2SA1015-R**, the specifications would look like this: | Parameter | Value | | :--- | :--- | | **Type** | PNP Epitaxial Silicon | | **Collector-Emitter Voltage (Vceo)** | -50V | | **Collector Current (Ic)** | -150mA | | **Power Dissipation (Pc)** | 400mW | | **Gain (hFE) for "R"** | 120 to 240 (Standard range) | --- ### Summary for Identification To find the exact datasheet, you need the numbers following the "2SA". For example, if the part is labeled **A1015 R**, you search for the **2SA1015** datasheet and look for the **"R"** classification in the "hFE" table.