Part Number: BDX54C

Function: -100V, -8A, PNP Epitaxial Silicon Transistor

Package: TO-220 Type

Manufacturer: Fairchild Semiconductor

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Description

The BDX54C is a PNP epitaxial silicon power Darlington transistor designed for high-voltage and high-current applications, with a collector-emitter voltage rating of -100V and current capability up to -8A. It features a Darlington configuration for high current gain and efficient amplification, making it suitable for power switching and linear operation. This device is commonly used in audio amplifiers, motor drivers, and general-purpose high-power control circuits.

Features

• PNP Darlington transistor with high current gain
• High voltage capability up to -100V
• Continuous collector current up to -8A
• Complementary pair with BDX53 series
• Suitable for linear and switching applications
• Robust power handling capability

Pinouts

Absolute Maximum Ratings (Tc = 25 °C)

How to Choose This Part

• Select for high-current PNP switching or amplification requirements
• Ideal when high gain is needed with minimal base drive
• Suitable for complementary pairing with BDX53 series
• Evaluate thermal design due to significant power dissipation
• Consider saturation voltage impact in efficiency-sensitive designs

Applications

• Hammer drivers and actuator control
• Audio amplifier circuits
• Power linear regulation
• Switching power stages
• Industrial control systems

Alternative / Equivalent Products

• BDX53C complementary NPN Darlington transistor
• TIP127 PNP Darlington transistor
• MJE2955 PNP power transistor
• MJ2955 high-power PNP transistor
• TIP125 Darlington transistor alternative

 

BDX54C Datasheet PDF Download

Other data sheets are available within the file: BDX54, BDX54A, BDX54B

This is a kind of PNP Transistor.

Part Number: B778, 2SB778

Function: PNP PLANAR TRANSISTOR ( Vceo = -120V )

Package: TO-3P Type

Manufacturer: Wing Shing Computer Components

See the preview image and the PDF file for more information.

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Description

The B778 (commonly referenced as 2SB778) is a PNP planar silicon power transistor designed for audio amplification and power conversion applications. It is typically used as the complementary pair to NPN transistors like 2SD998 or similar devices in push-pull amplifier configurations.

This device is optimized for high current handling and power dissipation, making it suitable for medium-to-high power analog and switching circuits.

1. High Current Capability

2. High Power Dissipation

B778 Pinout

Absolute Maximum Ratings

1. Collector-Base Voltage: Vcbo= – 120 V

2. Collector-Emitter Voltage: Vceo = – 120 V

3. Emitter-Base voltage : Vebo = – 6 V

4. Collector Current (DC) : Ic = – 10 A

5.Collector Dissipation : Pc = 80 W

6. Junction Temperature: Tj = 150°C

Design Notes (Critical Points)

• Heat sink is mandatory for high-power operation
• Use emitter resistors (~0.22Ω) for current balancing
• Ensure proper bias network to avoid crossover distortion
• Protect against overcurrent and thermal overload
• Maintain safe operating area (SOA) in linear mode

Typical Applications

• Audio power amplifier output stages
• Hi-Fi stereo systems
• DC-DC converter circuits (linear or low-frequency switching)
• High-current driver stages
• Power regulation circuits

Alternative / Equivalent Products

• 2SB817
• 2SA1941 (higher performance audio pair)
• TIP2955
• MJL1302A (high-end audio PNP)

B778 Datasheet