bd139 transistor

BD139 specification
- It is a bipolar NPN BJT Transistor
- DC Current Gain range is 25 to 250 hFE
- Collector current (IC) is 1.5A
- Collector to base Voltage (VCB) is 80V
- Collector to emitter Voltage (VEB) is 80V
- Emitter to base voltage (VEB) is 5V
- Base Current (IB) is 0.5A maximum
- Transition frequency (FT) is 50MHz
BD139 pinout
Pin Number | Pin Name | Description |
---|---|---|
Pin Number1 | Pin NameEmitter | DescriptionCurrent flows out through emitter |
Pin Number2 | Pin NameCollector | DescriptionCurrent flow through the collector |
Pin Number3 | Pin NameBase | DescriptionThe base terminal triggers the transistor |

BD139 package
- The BD139 transistor had TO-126 and TO-225 packages
- It is a rectangular-shaped transistor package and with a hole at the middle portion.
- The hole at the middle portion supports the transistor to mount it with the board or with the heat sink.
- The plastic-epoxy material usage will make the transistor more temperature resistant and compatible

If you need the datasheet in pdf please click this link
BD139 Description
- The Pinout of the BD139 is different, due to this reason the connection configuration will be different.
- The current gain range for the BD139 transistor will be 25 to 250hFE, and it is an important transistor value in terms of amplification.
- The peak collector current of the BD139 transistor is 1.5A, this value will be the peak current value for a transistor device.
- The peak base current of the BD139 transistor is 0.5A, the maximum allowable bias voltage on the trigger terminal.
- Maximum power dissipation at the BD139 transistor is 12.5w, this will show that it is a powerful transistor device.
- The transition frequency on the BD139 transistor is 50MHZ, it is an important factor at the transistor switching frequency.
- The maximum junction temperature at the BD139 transistor is 150°C.
BD139 transistor datasheet

If you need the datasheet in pdf please click this link
BD139 transistor Equivalent
- The transistor equivalent for BD139 transistor is BD169, BD179, BD230, MJE244, or MJE722.
- Each one at the equivalent list is the perfect equivalent for the BD139 transistor.
- Most of the electrical specifications and technical specifications of all of the transistors are the same.
BD139 vs BD140 vs MJE242 vs BD379
BD139 | BD140 (PNP) | MJE242 | BD379 | |
---|---|---|---|---|
Collector to base voltage (VCB) | BD13980V | BD140 (PNP)-80V | MJE24280V | BD379100V |
Collector to emitter voltage (VCE) | BD13980V | BD140 (PNP)-80V | MJE24280V | BD37980V |
Emitter to base voltage (VEB) | BD1395V | BD140 (PNP)-5V | MJE2427V | BD3795V |
Collector current (IC) | BD1391.5A | BD140 (PNP)1.5A | MJE2428A | BD3792A |
Power dissipation | BD13912.5W | BD140 (PNP)12.5W | MJE24215W | BD37925W |
Junction temperature (TJ) | BD139150°C | BD140 (PNP)150°C | MJE242150°C | BD379150°C |
Transition frequency (FT) | BD13950MHZ | BD140 (PNP)160MHZ | MJE24240MHZ | BD37950MHZ |
Noise (N) | BD139——– | BD140 (PNP)——- | MJE242——- | BD379——— |
Gain (hFE) | BD13925 to 250hFE | BD140 (PNP)25 to 250hFE | MJE24225 to 250hFE | BD37930 to 250hFE |
Package | BD139TO-126 TO-225 | BD140 (PNP)TO-126 | MJE242TO-126 | BD379TO-126 |
BD139 Application
- RF amplifier circuit
- Switching circuits
- Amplifier circuits
- Audio amplifier circuits
- Load driver circuits
- Arduino circuit applications
BD139 switch circuit
- The figure shows the basic model switch circuit using the BD139 transistor.
- Both the resistors used on the circuit is for driving transistor and LEDs
- At the time the switch closes, the resistor on the base of the transistor provides a voltage to trigger the BD139 transistor.
- And the trigger pulse reaches the LED, it starts glowing.

BD139 amplifier circuit
- The figure shows a mini amplifier circuit using a BD139 transistor.
- The amplifier circuit consists of two-stage of the transistor, 2n3904 and BD139 transistor.
- Both of the transistors are identical in technical specifications.
- The transistors are in a common emitter configuration, so when the input signal reaches the input capacitor, they bypass the signal to the Q1 transistor.
- The Q1 transistor amplifies the signal and forwards towards the second transistor Q2.
- The Q2 transistor BD139 makes second stage amplification and forwards to the output.

BD139 Arduino
- The figure shows the Arduino project using BD139 transistor, the BD139 transistor had applications on speed controlling projects.
- This particular circuit is for controlling the speed of the cooler, as we can see on the circuit, the BD139 is connected to the PMW terminal.
- The pulse based on the Arduino board, the BD139 transistor control the speed of the cooler.
