S8550 2TY PNP 40V 500mA 300mW Transistor SOT-23

S8550 2TY PNP 40V 500mA 300mW Transistor SOT-23 is a widely used general-purpose transistor, classifying as a medium-power PNP device designed for switching and amplification tasks in portable electronics. Featuring a collector current capability of 500 mA, the S8550 effectively manages moderate current loads in compact circuits. Consequently, manufacturers often select this transistor for applications where space is limited and reliable power handling is essential. The “2TY” marking identifies this specific SOT-23 package variant. Furthermore, its low saturation voltage ensures efficient operation, minimizing power loss during switching cycles, which is critical for battery-powered devices. Therefore, the S8550 offers excellent value and performance for various discrete semiconductor needs.

Key Features:

• High Collector Current: Handles a continuous collector current (I_C) up to 500 mA, suitable for driving LEDs, small relays, and moderate loads.
• Low Saturation Voltage: Achieves a low V_CE(sat), minimizing power dissipation and improving the efficiency of switching circuits.
• Small Surface Mount Package: The SOT-23 package drastically reduces the required PCB area, making it ideal for compact and miniaturized electronic products.
• Moderate Power Dissipation: Supports a collector power dissipation (P_D) up to 300 mW, offering robust performance for its size.
• High Voltage Rating: The 40 V collector-emitter voltage (V_CEO) accommodates common low-voltage supply rails up to 24V.

Technical Specifications:

• Transistor Type: PNP Silicon Epitaxial Transistor
• Collector-Base Voltage (V_CBO): 40 V
• Collector-Emitter Voltage (V_CEO): 25 V (Some datasheets specify 40 V, use 25 V for conservative design)
• Emitter-Base Voltage (V_EBO): 6 V
• Continuous Collector Current (I_C): 500 mA
• Power Dissipation (P_D): 300 mW (at T_A=25°C)
• DC Current Gain (h_FE): 85 to 300 (Depends on specific grouping)
• Transition Frequency (f_T): ≥ 150 MHz

Mechanical Specifications:

• Package Type: SOT-23 (Small Outline Transistor, 3-pin)
• Mounting: Surface Mount Technology (SMT/SMD)
• Marking Code: 2TY (Common code for S8550 in SOT-23)
• Maximum Junction Temperature (T_J): 150°C

Dimensions:

• Body Length: ≈ 2.9 mm
• Body Width: ≈ 1.3 mm
• Height: ≈ 1.0 mm
• Lead Pitch: ≈ 1.9 mm
• Footprint: Standard SOT-23 dimensions for automatic placement and reflow soldering.

Pinout and Wiring:

• Pin 1 (Base, B): Connect the control signal here (requires a small positive current relative to the emitter to turn ON).
• Pin 2 (Emitter, E): Connect this pin to the positive supply rail in a low-side switching configuration.
• Pin 3 (Collector, C): Connect to the load or the switched component (e.g., LED or motor coil).
• Wiring Note: Remember, as a PNP transistor, you drive the base low (towards the emitter potential) to turn the transistor ON.

Datasheet Reference:

• Download S8550 Transistor Datasheet

Commonly Used in:

• Consumer Electronics: Found in mobile phones, digital cameras, and audio amplifiers for general switching and driver tasks.
• Portable Devices: Used extensively in battery-powered applications due to its small size and efficient switching capability.
• LED Control: Drives segments of LED displays or acts as a high-side switch for general indicator LEDs.

Applications:

• Switching Circuits: Functions as a reliable electronic switch for currents up to 500 mA, driving relays or small solenoids.
• Amplification Stages: Provides pre-amplification or driver amplification in low-to-medium frequency audio and signal processing circuits.
• Voltage Regulation: Serves as a pass element in simple linear voltage regulators.
• Logic Interface: Translates low-current logic signals into sufficient current to drive output devices.

Equivalent Models:

• S9012 (PNP): A very common low-power PNP transistor, often considered a close functional equivalent, though with lower I_C and V_CE limits.
• 2SA1015 (PNP): A popular substitute, usually found in a larger TO-92 package but offering similar performance specifications.
• MMBT3906 (PNP): Another SOT-23 PNP general-purpose transistor, which engineers often use for low-current applications but has a lower I_C rating than the S8550.

Package Includes:

• 1 x S8550 2TY PNP Transistor SOT-23 (500mA, 40V)