The **D882-R** is a popular NPN Power Bipolar Junction Transistor (BJT) known for its high current capacity and low saturation voltage. It is frequently used in power management, motor control, and audio amplification circuits. --- ### 1. Key Technical Specifications The "R" suffix typically refers to the **DC Current Gain (hFE) classification**, indicating a specific range of gain. | Parameter | Symbol | Value | | :--- | :--- | :--- | | **Type** | - | NPN | | **Collector-Emitter Voltage** | $V_{CEO}$ | 30V | | **Collector-Base Voltage** | $V_{CBO}$ | 40V | | **Emitter-Base Voltage** | $V_{EBO}$ | 6V | | **Collector Current (DC)** | $I_C$ | 3A | | **Collector Current (Pulse)** | $I_{CP}$ | 7A | | **Power Dissipation** | $P_D$ | 1.25W (without heat sink) | | **Current Gain (hFE) Rank R** | $h_{FE}$ | 60 – 120 | --- ### 2. Pin Configuration The D882 is commonly found in the **TO-126** package (a medium-power plastic package). Looking at the labeled side with pins pointing down: 1. **Pin 1 (Emitter):** Connects to the ground or negative side of the load. 2. **Pin 2 (Collector):** Connects to the load. 3. **Pin 3 (Base):** The trigger pin that controls the transistor. --- ### 3. Core Features * **High Current Handling:** Despite its small size, it can handle up to 3A of continuous current, making it superior to general-purpose transistors like the BC547 or 2N2222. * **Low Saturation Voltage:** It has a very low $V_{CE(sat)}$, meaning it wastes less power as heat when fully turned on (switched). * **Complementary Pair:** The PNP equivalent is the **B772**, often used together in Push-Pull amplifier stages. --- ### 4. Common Applications * **Voltage Regulators:** Used in linear power supply circuits. * **Relay Drivers:** High current allows it to drive large industrial relays or solenoids. * **DC Motor Speed Control:** Used in H-bridge circuits or PWM motor drivers. * **Audio Amplifiers:** Specifically in the output stage of Class AB amplifiers. --- ### 5. Schematic Symbol (NPN) ```text C (Collector) | |/ B --| (Base) |\> | E (Emitter) ```