BD140 Bipolar Transistor PNP 80V 1.5A TO-126
BD140 Bipolar Transistor PNP 80V 1.5A TO-126 – High-Gain, Reliable Amplifier & Switching Solution is a versatile PNP bipolar junction transistor designed for amplification and switching applications. With a collector-emitter voltage rating of 80V and a continuous collector current of 1.5A, the BD140 is ideal for audio amplifiers, driver stages, power management circuits, and general-purpose electronic designs. Housed in a compact TO-126 package, it offers dependable performance, efficient thermal characteristics, and easy integration into both professional and hobby electronics projects.
Features
- PNP bipolar transistor for amplification and switching applications.
- High collector-emitter voltage rating of 80V.
- Supports continuous collector current up to 1.5A.
- Suitable for audio amplifier output and driver stages.
- Compact TO-126 package for efficient mounting.
- Reliable electrical performance and stability.
- Good gain characteristics for signal amplification.
- Compatible with a wide range of electronic circuits.
- Durable construction for long-term operation.
- Ideal for professional and DIY electronics projects.
Specifications
| Parameter | Details |
| Part Number | BD140 |
| Transistor Type | PNP Bipolar Junction Transistor |
| Package Type | TO-126 |
| Mounting Type | Through Hole |
| Collector-Emitter Voltage (VCEO) | 80V |
| Collector-Base Voltage (VCBO) | 80V |
| Emitter-Base Voltage (VEBO) | 5V |
| Collector Current (IC) | 1.5A |
| Power Dissipation (PD) | 12.5W |
| DC Current Gain (hFE) | 40 To 250 |
| Operating Temperature | -65°C To +150°C |
Dimensions
Pinout Configuration
|
Pin Number |
Pin Name |
Pin Description |
|
1 |
Emitter |
Current Drains out through emitter, normally connected to ground |
|
2 |
Collector |
Current flows in through collector, normally connected to load |
|
3 |
Base |
Controls the biasing of the transistor, used to turn ON or OFF the transistor. |
How to use BD140 Transistor
Transistors are current-controlled devices so to turn them on a little current is needed. For the BD140 Transistor, this base current is less than 10mA, as BD140 is a PNP transistor that means it will be on when the base is connected to the ground, and it will be off when a positive voltage is applied to the base of the transistor.
The simulated circuit below shows how this transistor behaves when the base of the basic circuit is connected to the ground and when it’s connected to 12V of the power supply.
When we turn on the transistor by connecting the base to the ground the transistor will remain on unless the voltage at the base of the transistor reaches more than the base turn-off voltage, for this transistor, it is somewhere in between 0.7 -0.9V. The base of the transistor cannot be left floating otherwise there could be false triggering, which may lead to issues in the circuit. To resolve this issue, we need to add pullup resistors as shown in the example, a 10K resistor is used to pull up the base of the transistor to VCC.
Applications
- Audio amplifier circuits.
- Power amplifier driver stages.
- Signal amplification circuits.
- General-purpose switching applications.
- Power supply control circuits.
- Motor driver circuits.
- Electronic control systems.
- Educational and laboratory projects.
- DIY electronics development.
- Complementary transistor pair designs with NPN transistors.