BC557 PNP Transistor

BC557 Transistor Specifications

General Information

• Type: PNP
• Package Type: TO-92 (through-hole) and other packages (SOT-23, SOT-223, etc.)
• Polarity: PNP

Electrical Characteristics

• Collector-Emitter Voltage (Vce): -45 V (maximum)
• Emitter-Base Voltage (Veb): -5 V (maximum)
• Collector Current (Ic): -100 mA (maximum)
• Power Dissipation (Pd): 500 mW (at 25°C)
• DC Current Gain (hFE): 100 to 600 (depending on Ic)
• Transition Frequency (fT): 100 MHz (typical at Ic = 10 mA)

Thermal Characteristics

• Operating Junction Temperature (Tj): -55 to +150 °C
• Storage Temperature (Ts): -55 to +150 °C

Electrical Characteristics (at 25 °C)

• Collector Cut-Off Current (Icbo): -0.1 µA (maximum at Vce = -45 V)
• Emitter Cut-Off Current (Ie): -0.1 µA (maximum at Veb = -5 V)
• Base-Emitter Cut-Off Current (Iebo): -0.1 µA (maximum at Veb = -5 V)
• Collector-Emitter Saturation Voltage (Vce(sat)): -0.25 V (maximum at Ic = -10 mA)
• Base-Emitter Voltage (Vbe): -0.7 V (typical at Ic = -10 mA)

Recommended Operating Conditions

• Collector Current (Ic): up to -100 mA
• Base Current (Ib): Typically less than 5 mA

Features

• Low Noise: Suitable for low-noise applications.
• High Voltage Rating: Can be used in circuits requiring high voltage handling.
• Complementary Pair: Often used with NPN transistor types like BC547.

Applications

• Amplifiers: Used in audio and RF amplification circuits.
• Switching: Suitable for switching applications in various electronic circuits.
• Signal Processing: Used in analog signal processing circuits.

Pin Configuration (TO-92 Package)

1. Emitter (E): The terminal through which current flows out.
2. Base (B): The control terminal that modulates the current.
3. Collector (C): The terminal through which current flows in.

Important Notes

• Ensure proper heat sinking if the power dissipation exceeds the specified limit.
• Handle with care to avoid static damage.
• Follow proper biasing techniques to ensure optimal operation in amplifying or switching configurations.

Typical Application Circuit

A common application involves using the BC557 as a switch, where a small current at the base controls a larger current flowing from the collector to the emitter.