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2N3771 Transistor: Pinout, Features, Applications, and Alternatives

NPN transistors are electronic components falling under Bipolar Junction Transistors. The type of transistor works by amplifying circuit applications, especially weak signals. 2N3771 transistor is an NPN transistor from NTE electronic. This article will expound on the definition, features, applications, alternatives, and pin configuration of 2N3771. 

What is a 2n3771 Transistor?

2N3771 transistor is a high current switching transistor in the TO-3 package often made from silicon. It is commonly applicable in power supply circuits and linear switching devices due to its collector current of 30A. 

TO-3 package of 2N3771 transistor

TO-3 package of 2N3771 transistor

Source; Wikipedia

It has three terminals whereby the collector is the transistor’s body, while the emitter and base terminals are leads. The structure is that the collector carries a high current in a large surface area. Therefore, the body will function as a heat sink. 

Additionally, a 2N3771 transistor package comes with mounting wires and kits that apply in testing boards alongside 2N3771. 

2n3771 Transistor Pin Configuration

2N3771 is a three-pin transistor NPN IC. Its pinout in the Jedec TO-3 2N3771 datasheet comprises the pin name descriptions below.

Pin1 / Base pin – Besides turning the transistor off and on, it also controls the biasing of the transistor.  

Pin2 / Collector pin – It connects to the load and allows current inflow. 

Pin3 / Emitter pin – The third pin connects to the ground and enables the outflow drain of current. 

The Features of the 2n3771 Transistor

  • First, it is a high-power NPN transistor available in the Jedec TO-3 metal case or TO-204AA package. 
  • Then, it has a maximum emitter-base voltage (VBE) of 5V. 
  • Also, its maximum operating junction temperature (Tj) is 200°C. 
  • Its transition frequency is 0.2 MHz, while its maximum collector power dissipation (Pc) is 150W. 
  • Its DC gain (hFE) ranges from 15 to 60, while its continuous collector current (IC) is 30A. 
  • Lastly, its collector-base voltage (VCB) is 50V, and its collector to emitter voltage (VCE) is also 50V. 

2n3771 Transistor Alternatives

Some alternatives of the 2N3771 transistor are NTE181, MJ14000G, 2N5685, MJ14002, 2N3771G, 2N5686, SK9134, 2N5302, MJ14000G, MJ14000, MJ14002G, and 2N5301. 

  1. Applications

Further on, you are most likely to find 2N3771 in the following applications. 

power supply printed circuit board

(power supply printed circuit board)


Briefly, 2N3771 is a silicon transistor type with low (less than 5V) base threshold voltage and high collector-emitter voltage (40V). Further, the ROHS3 compliant transistors mostly fall in inductive switching and linear amplifiers applications. In addition, its online prices (with relevant reviews for clients) are fair for tech projects. 

It is always a pleasure to respond to our clients with better solutions. Thus, if you have any component questions, need clarification, or a better product description, do reach out to us. 

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Emma Lu
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