The BD140 is a versatile PNP Transistor designed for audio amplifiers and drivers that use complementary or quasi-complementary circuits. It is available in the SOT-32 plastic package. The NPN complement of the BD140 is the BD139 transistor.

The PNP transistor means that its collector and emitter will be open when a positive voltage is applied to the base and will close when no voltage is present on the base. The transistor’s beta value can range from 40 to 160, determining its amplification factor. The maximum rated current for the BD140 is 1.5A, but power rating and temperature considerations should be taken into account. With a maximum base-emitter voltage of 5V, it is suitable for logic-level applications in embedded systems.

When the transistor is biased, it can allow a maximum of 1.5A to flow through its emitter-collector junction, which is known as the saturation state. Flowing more current than 1.5A can damage the device. When the base current is removed, the transistor becomes fully off, entering the cut-off region where no current flows through the device

Pinout Configuration

• Pin 1: Emitter – Current drains out through the emitter, usually connected to the ground.
• Pin 2: Collector – Current flows in through the collector, typically connected to the load.
• Pin 3: Base – Controls the biasing of the transistor, used to turn the transistor ON or OFF.

Features and Specifications of BD140 Transistor

• Bipolar PNP Transistor
• Continuous Collector current (IC): -1.5A
• Collector-Emitter voltage (VCE): -80V
• Collector-Base voltage (VCB): -80V
• Base Current (Ib): -0.5A
• Emitter Base Breakdown Voltage (VBE): -5V
• DC current gain (hfe): 40 to 160
• Available in TO-126 and SOT-32 packages
• Collector Dissipation: 12.5W
• Operating Junction Temperature Max (Tj): 150°C

Applications

The BD140 transistor is commonly used in the following applications:

• Moderate current switching applications
• High-current relay drivers
• Microphone preamplifiers
• Lighting systems
• Audio amplifiers
• Medium power linear and switching circuits
• Signal amplifiers

FAQs and Answers

Q: What is the pin configuration of the BD140 transistor?

A: The BD140 transistor has three pins: an Emitter (connected to the ground), a Collector (connected to the load), and a Base (used to control the transistor).

Q: What is the maximum collector current (IC) of the BD140 transistor?

A: The BD140 transistor has a maximum collector current (IC) of -1.5A.

Q: What is the collector-emitter voltage (VCE) of the BD140 transistor?

A: The collector-emitter voltage (VCE) of the BD140 transistor is -80V.

Q: Can I use the BD140 transistor for small signal switching?

A: Yes, the BD140 transistor can be used as a small signal-switching transistor.

Q: What is the base current (Ib) of the BD140 transistor?

A: The base current (Ib) of the BD140 transistor is -0.5A.

Q: What is the emitter-base breakdown voltage (VBE) of the BD140 transistor?

A: The emitter-base breakdown voltage (VBE) of the BD140 transistor is -5V.

Q: What is the DC current gain (hfe) range of the BD140 transistor?

A: The DC current gain (hfe) of the BD140 transistor ranges from 40 to 160.

Q: Are there equivalent transistors to the BD140?

A: Yes, the BD139, BD136, BD138, and D882 transistors are equivalent to the BD140.

Q: Can the BD140 transistor be used in audio amplifier applications?

A: Yes, the BD140 transistor is suitable for audio amplifier applications.

Q: What are some common applications of the BD140 transistor?

A: The BD140 transistor can be used in moderate current switching applications, high current relay drivers, microphone preamplifiers, lighting systems, audio amplifiers, medium power linear and switching circuits, and signal amplifiers.