BD440 Pinout, Equivalent, Uses, Features and Other Data

BD440 is a medium power PNP transistor available in TO-126 package. In this post we are going to discuss BD440 pinout, equivalent, uses, features and other info.


BD440 Pinout, Equivalent, Uses, Features and Other Data




Absolute Maximum Ratings:

  • Package Type: TO-126
  • Transistor Type:  PNP
  • Max Collector Current(IC): –4A
  • Max Collector-Emitter Voltage (VCEO): –60V
  • Max Collector-Base Voltage (VCBO): –60V
  • Max Emitter-Base Voltage (VEBO): –5V
  • Max Collector Power Dissipation (PC): 36W
  • Max Transition Frequency (fT): 3 MHz
  • Minimum & Maximum DC Current Gain (hFE): 20 – 140
  • Max Storage & Operating temperature Should Be: -65 to +150 Centigrade


NPN Complementary:

The NPN complimentary of BD440 is BD439


Replacement and Equivalent:

BD790, BD788, BD442, BD190, 2SB995, BD334, BD338, BD684, MJE703G, MJE235, MJE253, MJE233, MJE250, MJE253, MJE251, 2N4920, 2SB966.


BD439 Transistor Explained / Description:

BD440 is a medium power transistor available in TO-126 package. It is designed to be used in switching and amplifier applications. Moreover, the transistor has quite good characteristics which makes it ideal to use in wide variety of applications. Looking at the absolute maximum ratings of the transistors the maximum collector current of the transistors is 4A, the collector to emitter voltage is -60V, max emitter-base voltage is -5V, the total device dissipation is 36W, and base current is 1.0A. Now looking at the electrical characteristics the collector-emitter breakdown voltage is also -60V, collector-base break down voltage is also -60V. DC current gain is from 20 to 140 and collector saturation voltage is 0.8V.

BD440 is the transistor of BD4xx series which contains other transistors which are BD434, BD436, BD438, and 442. There are also PNP complimentary series of these transistors which contain Bd433, BD435, BD437, BD439, and BD441. These PNP complementary transistors can be paired with their NPN complementary transistors to provide efficient results and allow the designer or hobbyists to make efficient and reliable applications.


Where We Can Use it & How to Use:

The BD440 is mainly designed to be used in switching and amplification applications but it is not only limited to these applications and can also be used in wide variety of other applications for example Drivers, Controllers, PWM etc.

Using the transistor is the same as we use any other BJT transistor. First of all, check the pinouts then connect the emitter to the negative supply of the circuit, connect the base with the input signal (Use a suitable resistor between the input signal and the base of the transistor), and connect the collector pin with the negative supply of the load and the positive supply of the load will be connected with the positive supply of the circuit.



Solar Circuits

LED Drivers

Switching Circuits

Audio Amplifiers

Motor Drivers

Inverter Circuits

Relay Driver Circuits

PWM controllers

Inverter Circuits

Temperature Control Circuits

Many other General Purpose Applications


Safe Operating Guidelines:

Below are the guidelines to safely operate the transistor to get long term performance in the circuit.

  • Do not use the transistor to its absolute maximum ratings and always stay 20% below these ratings.
  • So according to the above 20% rule, the maximum derived load should be under 3.2A because the maximum collector current of the transistor is 4A.
  • Max load voltage should be under 48V because the max collector to emitter voltage is 60V.
  • The storage and operating temperature should be maintained between -65°C to 150°C.



To download the datasheet just copy and paste the below link in your browser.

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