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How to use 2n3906 PNP Transistor

What is 2N3096 Transistor

2N3906 is a widely used PNP bipolar junction transistor for general low power amplification or switching applications. It is specially designed for low current, low power and medium voltage, and can operate at medium speed. The current of collector is 200 mA, the voltage of collector base and collector emitter is 40 V, and the power consumption is 300 MW. Its conversion frequency ft is 250 MHz and beta is at least 100.

2N3906 has a gain of 110 to 300, which determines the amplification capability of semiconductor transistors. Its characteristic is that the maximum current through the collector pin is 200 mah, so we tend not to connect the load consuming more than 200 Ma to the semiconductor. In order to bias semiconductors, we must generate a current to the base, which should be limited to 5 ma.

2N3906 belongs to PNP semiconductor devices. Therefore, once the bottom pin is instructed to be grounded, the collector and emitter are closed (forward bias) and open (reverse bias) once symbols are provided to the base pin. This is usually where the PNP transistor semiconductor device is different from the NPN transistor. The logical state (blue) is used to switch between the ground voltage and the signal voltage (emitter base voltage vbe).

When the transistor is completely biased, it can allow up to 200 mA of current to flow through the collector and emitter. This stage is called saturation zone. Typical voltages through Collector Emitter (V-CE) or base emitter (VBE) are 40 and 5 V, respectively. When the base current is removed, the transistor is completely closed. This stage is called cut-off zone. The base emitter voltage may be about 5V.

2N3906 Features

  • Categories: Discrete Semiconductor Products  
  • Mounting Style:  Through Hole 
  • Package / Case:  TO-92-3 
  • Transistor Polarity:  PNP 
  • Configuration:  Single 
  • Collector- Emitter Voltage VCEO Max:  40 V 
  • Collector- Base Voltage VCBO:  – 60 V 
  • Emitter- Base Voltage VEBO:  – 6 V 
  • Maximum DC Collector Current:  0.2 A 
  • Gain Bandwidth Product fT:  250 MHz 
  • Minimum Operating Temperature:  – 65 C 
  • Maximum Operating Temperature:  + 150 C 
  • Series:  2N3906 
  • DC Current Gain hFE Max:  300                       
  • Height:  4.95 mm                       
  • Length:  4.95 mm                       
  • Packaging:  Bulk                       
  • Width:  3.94 mm                       
  • Brand:  STMicroelectronics                       
  • Continuous Collector Current:  0.2 A                       
  • DC Collector/Base Gain hfe Min:  30                       
  • Pd – Power Dissipation:  625 mW                       
  • Product Type:  BJTs – Bipolar Transistors                       
  • Factory Pack Quantity:  2500                       
  • Subcategory:  Transistors                       
  • Unit Weight:  0.016000 oz                       
  • Bi-Polar PNP Transistor
    DC Current Gain (hFE) is 300 maximum
    Continuous Collector current (IC) is 200mA
    Emitter Base Voltage (VBE) is 5V
    Base Current(IB) is 5mA maximum
    Collector Emitter Voltage (VCE) is 40V
    Collector Base Voltage (VCB) is 40V
    Available in To-92 Package
    silicon epitaxial planar npn transistor
    to-92 package suitable for through-hole pcb assembly
    the npn complementary type is 2n3906

Where to use 2N3906

The 2N3906 is a commonly used PNP transistor. It very much similar to the bc557 transistor except for that it has high collector to emitter voltage and hence high voltage loads can be toggled. This transistor has only a gain value of 300, hence not suitable for amplifier circuits. So if you looking for a PNP transistor that could switch high voltage loads within 0.2A then this 2N3906 transistor might be the right choice for you.


  • well suitable for tv and home appliance equipment
  • small load switch transistor with high gain and low saturation voltage
  • Used to switch high voltage low current loads
  • Optimal for loads with high peak voltage upto 40V
  • It is used in the various switching applications.
  • Used in inverter and converter circuits
  • Used for making siren or dual Led or Lamp flasher.
  • Can be used in Darlington Pair.

2N3906 PNP Circuit

Below is the circuit for connecting a PNP transistor, which can function as a switch or an amplifier.

So +3V is connected to the emitter of the transistor. And a normally open pushbutton is connected to the base of the transistor. Unless it is pressed, normally no current flows into the base of the transistor. Thus, it is fully on when not pressed. Therefore, the LED connected to the collector of the PNP transistor will be on. However, if the push button is pressed, the transistor will turn off and the LED will shut off. This is because the base voltage will be greater than the emitter voltage, which blocks current flow.

2N3906 PNP Circuit
2N3906 PNP Circuit

And this is how a basic PNP transistor circuit works.

2N3906 Equivalent Transistors: 2N4403, MPSA13, MPSA92, MPSA55, ZTX555

Alternative for 2N3906: BC157, BC558, 2SA1943, BD140, S8550, TIP127, TIP42

The complementary NPN transistor vs the 2N3906 is the 2N3904. Both types were registered by Motorola Semiconductor in the mid-1960s.


1 thought on “How to use 2n3906 PNP Transistor

  1. 2N3906 is a PNP transistor and mainly used for low power amplification and switching purpose. Detail knowledge about 2n3906 !

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