## Technical Overview: 2SD601-R Transistor The **2SD601-R** is a high-frequency, low-noise NPN epitaxial silicon transistor. It is primarily designed for use in low-frequency amplification and switching applications within compact electronic devices. --- ### 1. Key Features and Identification * **Polarity:** NPN * **Package Type:** Mini-type (usually SOT-23 / SC-59 / SMini3-G1). * **Complementary Pair:** Often paired with the **2SB709** (PNP). * **"R" Marking:** The suffix "R" typically denotes the **hFE (DC Current Gain)** classification, which falls within a specific range (usually 210 to 340). ### 2. Absolute Maximum Ratings ($T_a = 25^\circ\text{C}$) | Parameter | Symbol | Rating | Unit | | :--- | :--- | :--- | :--- | | Collector-Base Voltage | $V_{CBO}$ | 60 | V | | Collector-Emitter Voltage | $V_{CEO}$ | 50 | V | | Emitter-Base Voltage | $V_{EBO}$ | 7 | V | | Collector Current | $I_C$ | 100 | mA | | Total Power Dissipation | $P_C$ | 150 | mW | | Junction Temperature | $T_j$ | 150 | $^\circ\text{C}$ | ### 3. Electrical Characteristics | Characteristic | Symbol | Test Condition | Min | Max | Unit | | :--- | :--- | :--- | :--- | :--- | :--- | | DC Current Gain | $h_{FE}$ | $V_{CE}=10\text{V}, I_C=2\text{mA}$ | 210 | 340 | - | | Transition Frequency | $f_T$ | $V_{CE}=10\text{V}, I_C=2\text{mA}$ | 150 | - | MHz | | Collector-Emitter Sat. Voltage | $V_{CE(sat)}$ | $I_C=100\text{mA}, I_B=10\text{mA}$ | - | 0.3 | V | | Collector Cut-off Current | $I_{CBO}$ | $V_{CB}=45\text{V}, I_E=0$ | - | 0.1 | $\mu\text{A}$ | --- ### 4. Typical Applications 1. **Small Signal Amplification:** Due to its low noise and high gain, it is ideal for pre-amplifier stages in audio and radio equipment. 2. **General Switching:** Used in digital circuits to act as a switch for low-power loads (up to 100mA). 3. **High-Density Mounting:** Its small surface-mount footprint makes it suitable for modern cellular phones, cameras, and portable electronics. ### 5. Pinout Configuration Looking at the top of the SOT-23 package: 1. **Base (B)** 2. **Emitter (E)** 3. **Collector (C)** (The single pin on the opposite side) ---