Transistor 2N3906: Pinout, Equivalent and Specs

This text contains the technical documentation of the transistor 2N3906: its description, pinout, equivalents for replacement. It is intended for control circuits in which switching speed is important. It is manufactured by epitaxial-planar technology from silicon and has p-n-p structure. Low power, high frequency. Main features: high gain (up to 400 HFE), low collector saturation voltage (0.4 V) and low intrinsic noise (up to 4 dB).


We will consider the 2N3906 pinout in a TO-92 package. This package has three flexible pins for hole mounting. If you look directly at the beveled part on the marked side, the leftmost pin is the emitter, the middle one is the base, and the right one is the collector.


Fairchild Semiconductor, Jiangsu Changjiang Electronics Technology, Daya Electric Group, General Semiconductor, Silicon Standard, Daya Electric Group, GUANGDONG HOTTECH INDUSTRIAL, SHENZHEN KOO CHIN ELECTRONICS also produce this product in SOT-23. Fairchild Semiconductor has them in SOT-223. These plastic packages, with three short pins, are designed for surface mount (SMD) applications.


The maximum permissible specifications of the transistor, all known manufacturers, are specified at the very beginning of the technical description. They are designed for ambient temperatures up to +25°C. The values of these parameters must not be exceeded:

  • the voltage between the collector and the base is maximum VCBO (Ukb max) – 40 V;
  • voltage between collector and emitter maximum allowable VCEO (Uke max) = -40 V;
  • the voltage between the emitter and the base is the maximum possible VEBO (Ueb max) = -5 V;
  • maximum allowable DC collector current IC (Ik max) = -100 mA;
  • short-term collector current maximum ICP (Ik peak) = -200 mA;
  • the maximum possible power of the RSk max) = 500 mW;
  • temperature: crystal TJ (TK) up to 150 °C; TSTG storage (TXP.); possible working TAMB (TRAB.) – 55 … 150 °C.

It is worth bearing in mind the constant improvement of component designs by manufacturers. Therefore, there are some 2N3906 with improved specifications. Most often the temperature range of storage and use from – 65 to + 150°C, the maximum power up to 625 mW, and the peak collector current up to 300 mA are most often increased.

2N3906 max current:

  • Max – 100mA
  • Peak – 200mA


Let’s consider the electrical parameters that are indicated in the datasheet in a separate summary table, as a rule, after the maximum allowable. They are presented together with additional test conditions highlighted in a separate column and ambient temperature not exceeding +25°C.


The following transistors are equivalents of 2N3906: 2N2907, 2N3638, 2N3905, 2N3906RA, 2N4125, 2N4248, 2N4249, 2N4403, BC307, BC327, MPS3638, MPS3906, MPS6517, MPS6562, MPSA56.

You can find similar ones among different manufacturers. They have the same body, but differ slightly in their specifcations. Such closest equivalents are: 2N2906, MPSA70. And among the Russian products, very similar to the considered, can be called: KT313B, KT361G, KT6136A.

All manufacturers advise using 2N3903 and 2N3904 as a complementary pair.

Examples of Applications

This transistor is very often used for teaching purposes. If you are a beginner you can build a simple circuit with a blinking LED on it. A step by step instruction on how to assemble it can be seen in the video below.

The Manufacturers

Produce 2N3906 involved in a lot of companies, for the correct use of the component need to study exactly the datasheet from your transistor. You can download and view all datasheet for the 2N3906 from this link.

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