BC858B Transistor 3K PNP 30V 100mA 300mW SOT-23

BC858B Transistor is a general-purpose PNP junction transistor (BJT) designed for low-power switching and amplification in surface-mount applications. Packaged in a compact SOT-23 case, it offers moderate current handling, good gain, and is widely used in signal processing, control circuits, and consumer electronics.

Key Features:

• PNP Polarity: Complements NPN devices like BC848 for push-pull configurations.
• Low Collector-Emitter Voltage: Maximum V_CE of 30V.
• Decent Current Handling: Supports continuous collector current up to 100mA.
• Good Power Dissipation: Rated up to 300mW total power at 25°C ambient.
• Surface-Mount Package: Space-saving SOT-23 for high-density PCB layouts.

Technical Specifications:

• Type: PNP BJT
• Collector-Emitter Voltage (V_CE): -30V
• Collector Current (I_C): -100mA (max)
• Total Power Dissipation: 300mW
• DC Current Gain (h_FE): 200 – 450 (at I_C = 2mA)
• Transition Frequency (f_T): 100MHz (typical)
• Package: SOT-23
• Mounting: Surface Mount (SMT)

Pin Configuration (SOT-23):

• Pin 1: Base
• Pin 2: Emitter
• Pin 3: Collector

Schematic Diagram, Connection, Wiring and Pinout:

• Configuration: Common emitter is most commonly used for amplification.
• Wiring: Base connected via bias resistor, emitter to ground or negative rail.
• Symbol: PNP transistor symbol with emitter arrow pointing toward base.

Datasheet and Documentation:

• Download BC858B Transistor Datasheet (PDF)

Applications:

• Signal Switching: Suitable for low-power analog and digital signal control.
• Amplification: Used in low-frequency preamplifier and audio stages.
• Logic Level Shifting: Acts as a level converter in interfacing applications.
• Push-Pull Circuits: Complements BC848 in Class B or AB configurations.
• Mobile & Portable Devices: Compact size ideal for handheld electronics.

Equivalent Models:

• BC856B: Similar PNP transistor with slightly lower h_FE range
• MMBT2907A: General-purpose PNP in SOT-23 with higher current rating
• S9012: Economical PNP surface mount transistor for similar applications

Package Includes:

• 1 x BC858B Transistor 3K PNP 30V 100mA 300mW SOT-23