BD140 Bipolar Transistor PNP 80V 1.5A TO-126

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. Datasheet BD140

BD140 PNP Bipolar Power Transistor TO-126 (1.5A, 80V) The BD140 is a PNP Epitaxial Planar Transistor that is mounted in the TO-126 plastic package. They are designed for audio amplifiers and drivers utilizing complementary or quasi-complementary circuits. The NPN complement is BD139 and this transistor comes with a VCE of -80V and a continuous collector current of -1.5A. It can be used as a small signal switching transistor. Moreover, it has a low base voltage of -5V. BD140 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. Features and Specifications Bi-Polar PNP Transistor Continuous Collector current (IC) is -1.5A Collector-Emitter voltage (VCE) is- 80 V Collector-Base voltage (VCB) is- 80V Base Current (Ib) is -0.5A Emitter Base Breakdown Voltage (VBE) is -5V DC current gain (hfe) is 40 to 160 Available in TO-126 Package Collector Dissipation: 12.5 W Operating Junction Temperature Max (Tj): 150°C Note: Complete Technical Details can be found in the BD140 datasheet given at the end of this page. Overview of BD140 Transistor The BD140 transistor is a very versatile transistor that can be used in many different applications. This is a PNP transistor hence its collector and emitter will be left open when a positive voltage is applied to the base of the transistor, and it will close when no voltage is present on the base. The Beta value of this transistor can be anywhere between 40 to 160, this parameter determines the amplification factor of the device, the max rated current for this transistor is 1.5A. So we can connect a load up to 1.5A but we do need to consider the power rating and the temperature. This transistor has a maxim base-emitter voltage of 5V that means it can be suitably used for logic level application in embedded system. When this transistor is in a biased condition, it can allow a maximum of 1.5A through its emitter-collector junction, this state of the device is called the saturation state, flowing more current than 1.5A can damage the device. When the base current is removed the transistor becomes fully off, this stage is called the Cut-off Region so no current flows through the device. The BD140 was originally manufactured by Phillips rated at 160MHz for specific audio applications, later they were cloned by other manufacturers like Samsung, ST, ON Semi, etc. 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 Moderate Current switching applications High Current Relay Driver Microphone preamplifiers Lighting systems Audio Amplifiers Medium Power Linear and switching Signal Amplifiers Component Datasheet BD140 Datasheet