BD139 NPN transistor - 80 V, 1.5 A, TO-92

Product Overview

• Bipolar NPN transistor for switching and amplifying currents up to 1.5 A
• Breakdown voltage up to 80 V
• Current gain of approximately 40 to 250
• TO-92 plastic package with three terminals
• Suitable for prototyping and development on breadboards and circuit boards

Product Description

An NPN transistor from this series switches and amplifies DC currents up to 1.5 A in analog and digital circuits. The maximum permissible breakdown voltage of 80 V enables use in many standard electronics applications with operating voltages of up to approximately 60 V. The TO-92 package fits directly onto breadboards and simplifies the assembly of test circuits.

The transistor functions as a controlled current source. A small base current opens or closes the current flow between the collector and emitter. The current gain is within the usual range and enables base currents in the milliampere range for control. This makes the component ideal for controlling relays, motors, and LEDs from microcontroller outputs, as well as for signal amplification in multistage amplifier circuits.

Typical applications include controlling an LED matrix or a small motor from a microcontroller board, amplifying sensor signals before processing, or controlling relay coils as an interface to higher voltages and currents. The low thermal load during short-term applications such as signal amplification does not require cooling measures.

For stable operation, the base and collector resistors should be dimensioned according to the intended operating conditions. A protection diode in parallel with the coil is required when controlling inductive loads such as relays or motors. The manufacturer's datasheet contains the exact electrical specifications for limiting conditions and high-frequency applications above approximately 10 kHz.

Safety Information

Observe the correct polarity when installing the component in the circuit; reversing it can cause the transistor to fail. The product is intended exclusively for prototyping and testing and development purposes. It is not intended for installation in household mains circuits.

Scope of Delivery

• 1x BD139 - Bipolar NPN transistor, 80V, 1.5A