BD140 pinout

BD140 Transistor Datasheet and Equivalent

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The BD136, BD138 and BD140 are medium−power (1.5A) silicon epitaxial planar PNP transistors in TO126 plastic package, designed for audio amplifiers and drivers utilizing complementary or quasi complementary circuits. The complementary NPN types are the BD135 BD137 and BD139. This transistors mostly used in general switching and audio signal amplifications.

High Current Handling: With a maximum collector current of 1.5A, it can handle significant current levels, making it suitable for various power applications.

BD135, BD137, BD139 are NPN complementary of this

  • Material : Si
  • Type : PNP
  • Collector Current IC 1.5 A
  • DC Current Gain − hFE = 40 (Min), 250(max)
  • Collector−Emitter Voltage VCEO :80V 
  • Collector−Base Voltage VCBO : 100v
  • Emitter−Base Voltage VEBO : 5.0
  • Operating and Storage Junction Temperature Range : -55 to 150ºC

Collector−Emitter Voltage VCEO : 80V

BD136: 45V

BD138: 60V

BD140: 80V

Collector−Base Voltage VCBO : 100v

BD136: 45V

BD138: 60V

BD140: 100V

Uses and Applications of BD140 transistor

  1. Audio Amplifiers:
    • Driver Stages: The BD140 is commonly used in the driver stages of audio power amplifiers, where it helps drive the final output transistors.
    • Push-Pull Amplifiers: It can be paired with its complementary PNP transistor (e.g., BD139) in push-pull amplifier circuits to achieve efficient and linear amplification of audio signals.
  2. Switching Applications:
    • Relay Drivers: The BD140 can drive relays and other high-power devices in various switching applications.
    • Motor Drivers: It can be used in circuits to control small motors, making it suitable for motor driver applications.
  3. Voltage Regulators:
    • The BD140 can be used in voltage regulator circuits to maintain a stable output voltage, especially in power supply designs.
  4. Power Management:
    • Power Supply Circuits: It is used in the regulation and distribution of power within electronic devices.
    • DC-DC Converters: The transistor can be part of DC-DC converter circuits, which are essential in many electronic devices for voltage step-up or step-down applications.
  5. General-Purpose Switching:
    • The BD140 can switch various loads in electronic circuits, making it versatile for numerous applications where switching is required.
  6. Signal Amplification:
    • Pre-amplifiers: It can be used in pre-amplifier stages to amplify weak signals before further processing.
    • Intermediate Stages: The BD140 can be employed in intermediate amplification stages in multi-stage amplifier circuits.

Equivalent Of BD140 Transistor

BD136, BD138, SK100, TIP32C (pin BCE), TIP127(pin BCE)


SOT32 TO126 TO225


Datasheet BD140 BD136 BD138 (ST)




Datasheet BD140 BD138 BD136 (CDIL india)


Datasheet BD140 BD138 BD136 (ON)






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