2N2222 NPN Transistor

• 2N2222 NPN Transistor
• 2N2222A is a NPN transistor hence the collector and emitter will be left open (Reverse biased) when the base pin is held at ground and will be closed (Forward biased) when a signal is provided to base pin. 2N2222A has a gain value of 110 to 800, this value determines the amplification capacity of the transistor. The maximum amount of current that could flow through the Collector pin is 800mA, hence we cannot connect loads that consume more than 800mA using this transistor. To bias a transistor we have to supply current to base pin, this current (I_B) should be limited to 5mA.
• When this transistor is fully biased, then it can allow a maximum of 800mA to flow across the collector and emitter. This stage is called Saturation Region and the typical voltage allowed across the Collector-Emitter (V­_CE) or Base-Emitter (V_BE) could be 200 and 900 mV respectively. When base current is removed the transistor becomes fully off, this stage is called as the Cut-off Region and the Base Emitter voltage could be around 660 mV.

Alternative

• BC549, BC636, BC639, BC547, 2N2369, 2N3055, 2N3904, 2N3906, 2SC5200

2N2222A Equivalent Transistors

• 2N2907(PNP), 2N3904(PNP), 2N3906 (PNP), BC637, S9014, BC148, 2N4403, MPS2222, PN2222, KN2222, KTN2222

Applications

• Can be used to switch high current (upto 800mA) loads
• It can also be used in the various switching applications.
• Speed control of Motors
• Inverter and other rectifier circuits
• Can be used in Darlington Pair.