The **Z3Y-R** (often labeled simply as **Z3Y**) is the marking code for the **S8050** NPN epitaxial silicon transistor, typically found in the **SOT-23** surface-mount package. It is one of the most common low-voltage, high-current small-signal transistors used in consumer electronics. --- ### 1. Technical Specifications The following table outlines the absolute maximum ratings and electrical characteristics for the Z3Y (S8050) transistor: | Parameter | Symbol | Value | Unit | | :--- | :--- | :--- | :--- | | **Type** | - | NPN | - | | **Collector-Base Voltage** | $V_{CBO}$ | 40 | V | | **Collector-Emitter Voltage** | $V_{CEO}$ | 25 | V | | **Emitter-Base Voltage** | $V_{EBO}$ | 5 | V | | **Collector Current (DC)** | $I_C$ | 500 (up to 700) | mA | | **Collector Power Dissipation** | $P_C$ | 300 | mW | | **DC Current Gain** | $h_{FE}$ | 120 - 400 | - | | **Transition Frequency** | $f_T$ | 150 | MHz | --- ### 2. Pinout Configuration The Z3Y uses the standard SOT-23 footprint. When looking at the top of the component (with the single pin at the top): 1. **Pin 1 (Left):** Base (B) 2. **Pin 2 (Right):** Emitter (E) 3. **Pin 3 (Top):** Collector (C) --- ### 3. Key Features and Applications The Z3Y is favored in circuit design due to its high collector current ($I_C$) relative to its small size, allowing it to drive loads that standard signal transistors (like the 2N3904) cannot. * **Switching:** Used as a switch to control small DC motors, relays, or LED strips. * **Amplification:** Ideal for low-power audio amplification and signal processing. * **Voltage Regulation:** Often found in the regulation stages of battery-powered devices. * **Complementary Pair:** It is frequently paired with the **S8550 (Marking: 2TY)**, which is its PNP counterpart. --- ### 4. Comparison with Similar Transistors While many transistors share the SOT-23 package, their power handling capabilities vary: | Part Number | Marking Code | Type | Max $I_C$ | | :--- | :--- | :--- | :--- | | **S8050** | **Z3Y** | **NPN** | **500mA** | | **S8550** | 2TY | PNP | 500mA | | **SS8050** | Y1 | NPN | 1.5A | | **MMBT3904** | 1AM | NPN | 200mA | ---