### Overview of the 2SB1260-R The **2SB1260-R** is a Silicon PNP Epitaxial Planar Transistor designed primarily for power amplification and switching applications. It is known for its high current capacity and low saturation voltage, making it ideal for battery-driven portable equipment. --- ### Technical Specifications The "R" suffix typically refers to the **hFE (DC Current Gain)** classification, which usually falls within a specific range defined by the manufacturer (ROHM Semiconductor is the primary producer). | Parameter | Symbol | Maximum Rating | Unit | | :--- | :--- | :--- | :--- | | Collector-Base Voltage | $V_{CBO}$ | -80 | V | | Collector-Emitter Voltage | $V_{CEO}$ | -80 | V | | Emitter-Base Voltage | $V_{EBO}$ | -5 | V | | Collector Current (DC) | $I_C$ | -1 | A | | Collector Current (Pulse) | $I_{CP}$ | -2 | A | | Total Power Dissipation | $P_D$ | 1.0 (on Alumina PCB) | W | | Junction Temperature | $T_j$ | 150 | °C | --- ### Key Features * **Low Saturation Voltage:** Typically $V_{CE(sat)} = -0.4V$ at $I_c = -500mA$, which reduces power loss and heat generation. * **High Current Capability:** Despite its small footprint, it handles up to 1A continuous current. * **Complementary Pair:** The NPN counterpart for this transistor is the **2SD1898**. * **Package Type:** Usually found in the **SOT-89** (MPT3) surface-mount package, which offers good thermal dissipation for its size. --- ### Classification of Gain (hFE) Transistors in this series are categorized by their DC current gain. The "R" rank indicates the following: | Rank | Q | **R** | S | | :--- | :--- | :--- | :--- | | **hFE Range** | 120 - 270 | **180 - 390** | 270 - 560 | --- ### Common Applications 1. **Voltage Regulation:** Used in linear regulators for noise-sensitive circuits. 2. **Power Switching:** Driving LEDs, relays, or small motors in battery-operated devices. 3. **Audio Amplification:** Low-power output stages or driver stages. 4. **DC-DC Converters:** Efficiency-focused switching roles due to low $V_{CE(sat)}$. --- ### Pinout Configuration (SOT-89) When looking at the front (labeled side) with pins pointing down: 1. **Base (B):** Left Pin 2. **Collector (C):** Middle Pin (also connected to the large heat-sink tab) 3. **Emitter (E):** Right Pin