BC557 PNP Transistor (TO-92)

The BC557 is a general‑purpose BJT PNP transistor in a compact TO‑92 package, ideal for amplification and switching tasks in analog and digital electronics. With up to -45 V collector‑emitter voltage, -100 mA collector current, and a high transition frequency (fT) up to 150 MHz, it’s a dependable choice for electronics components in hobbyist projects and professional designs alike. Perfect for interfacing with microcontroller platforms where precise control and reliable switching are required.

Key Features ✨

• PNP transistor for general-purpose amplification and switching applications.
• TO‑92 through-hole package for easy breadboarding and PCB integration.
• VCEO up to -45 V supports a wide range of low-voltage to moderate-voltage designs.
• IC up to -100 mA suitable for small-signal load driving and high-side switching.
• DC current gain (hFE) 110–800 depending on grade (A/B/C), enabling efficient drive with modest base current.
• High fT up to 150 MHz for wideband signal processing and clean amplification.

Technical Specifications 📋

• Transistor Type: BJT PNP
• Package: TO‑92
• Collector‑Emitter Voltage (VCEO): -45 V
• Collector‑Base Voltage (VCBO): -50 V
• Emitter‑Base Voltage (VEBO): -5 V
• Collector Current (IC): -100 mA
• Power Dissipation (PD): 500 mW
• DC Current Gain (hFE): 110 to 800
• Transition Frequency (fT): 150 MHz
• Typical Pinout (TO‑92, flat side facing you): C — B — E (verify with the manufacturer’s datasheet)

Applications 🧰

Versatile and easy to drive, the BC557 fits a wide range of analog and digital designs:
Audio amplification stages and preamplifiers

• Signal processing and conditioning circuits
• Switching circuits and high-side control for small loads
• Power management, bias networks, and reference circuits
• General-purpose amplification in electronics modules