- Applications requiring switching and VHF (very high frequency) amplifiers are where NPN transistors like the 2N2222 are most frequently used. Silicon material can be used in the transistor’s design. As it is used like an NPN transistor because it is a normal type of transistor, It frequently serves as a small signal transistor. A 2N2222A transistor overview is covered in this article.
What is a 2N2222A Transistor?
- The 2N2222A transistor is a typical NPN BJT and is mostly utilized in low-power switching and amplifying applications. This transistor works at reasonably high speeds and is primarily intended for low power, low to medium current, and medium voltage applications.
- One P-doped layer is sandwiched between two N-doped layers of the 2N2222 NPN transistor. Base, Emitter, and Collector are three of the terminals on this transistor. Below is a symbol for a 2N2222A transistor.
- Since the 2N2222A transistor has a constant DC collector current of about 800mA, it must be used in applications requiring low to medium current. It operates at a high transition frequency of 250 MHz with delay times of 10 ns, storage times of 225 ms, fall times of 60 ms, and rising times of 25 ms. You can get it with the TO-92 bundle.
- Alternative 2N2222A transistors are; BC636, BC549, BC639, 2N2369, BC547, 2N3055, 2N3906, 2N3904 & 2SC5200. Equivalent 2N2222 transistors are; 2N3904 (PNP), 2N2907 (PNP), 2N3906 (PNP), S9014, BC637, BC148, MPS2222, 2N4403, PN2222, KTN2222 & KN2222.
2N2222A Transistor Pin Configuration
The pin configuration of the 2N2222A transistor is shown below. This transistor includes three pins & each pin’s functionality is discussed below.
- Pin1 (Collector): This is the first pin of the transistor & it is an o/p pin. The main function of this pin is to provide transistor current toward the o/p load.
- Pin2 (Base): The base pin is a control pin & it is a second pin of the transistor. The main function of this pin is to control the current from the emitter to the base.
- Pin3 (Emitter): The emitter pin is the third pin of the transistor & it is used to drain out the complete current of the transistor.
Features & Specifications of 2N2222A Transistor
The features & specifications of the 2N2222 NPN transistor include the following.
- The polarity of Transistor – NPN.
- Type of termination –Through Hole.
- Configuration of pin – a.
- Number of Pins -3.
- The voltage from collector terminal to emitter is 50V once the base terminal is open.
- The voltage from the emitter to the base terminal is 6V once the collector terminal is open.
- The voltage from the collector terminal to the base is 75V once the emitter terminal is open.
- The current Gain of DC is 100.
- DC collector current is 800mA.
- Accessible in the Package of To-92.
- Total power dissipation is 1W.
- The maximum base current is 5mA.
- Input capacitance is 25pF.
- Fall time is 60ns.
- Output capacitance is 8pF.
- Turn-on time is 25ns.
- The 2N2222 NPN transistor has a common emitter (CE), common collector (CC), and common base configuration modes (CB). These three arrangements may readily amp up voltage, current, and power in a variety of applications depending on the situation.
How to use 2N2222A Transistor?
- The touch switch circuit using the 2N2222A transistor circuit is shown below. This simple circuit is very helpful to turn on a relay in place of an LED & resistor to connect any appliance or load to operate through it.
- The required components of this circuit include input DC supply-6v, 2N222 transistors-2, resistors-330Ω, 200KRΩ & LED-1.
- Because a Darlington pair of two transistors may be used to construct this circuit, it is extremely responsive. The gain is amplified by the first transistor in the circuit, and it is then multiplied by the second transistor. to enable the achievement of high gain. This low gain makes the basic circuit incredibly responsive to the tiny current that turns on the LED.
- This circuit can operate with 6V, 9V, or 12V of power. When using 6V, a 330 resistor is required, whereas 390/470 resistors are required when using 9V or 12V, respectively.
- If a relay is used in the circuit in place of the LED and resistor, you must use the same relay voltage as the i/p voltage. The 200K variable resistor is used to control the circuit sensitivity.
- When one of the circuit’s touchpoints is touched, a small amount of electricity is supplied throughout the circuit, turning on the LED. This circuit is mostly used in lighting, locks, doors, and safety boxes.
Characteristics of 2N2222A Transistor
The key characteristics of 2N2222A are discussed below.
- The transistor’s completer power should not go above 500mW.
- The maximum handling frequency capacity is 250MHz.
- The maximum tolerance is 60V across its two terminals like base & collector.
- For the 10mA collector current & for 10V, the DC is approximately 75mA.
Advantages of 2N2222A Transistor
The main advantages of using the 2N2222 transistor include the following.
- This is the most commonly used type of transistor.
- In electronic circuits, most of the switching applications can be done by using this transistor.
- It is capable of handling fairly high magnitude currents as compared to other similar transistors.
- This transistor switches the load current with 800 mA through it, which is high as compared to others.
- So this capability will make the device ideal in the applications of linear amplifiers.
- Small size.
- Less weight.
- Voltage gain is high.
- Low source voltage.
- Low cost.
- Longer life.
Disadvantages of 2N2222A Transistor
The main disadvantages of using the 2N2222A transistor include the following.
- Depends on Temperature.
- Input impedance is low.
- Faults cannot be found easily due to the small size.
- It is extremely hard to replace with new ones by unsoldering.
- It does not function efficiently like a relay or electrical, mechanical switches.
Applications of 2N2222A Transistor
The applications of the 2N2222A transistor include the following.
- As compared to the normal NPN BC547 transistor, the 2N2222 is extremely similar, but 2N2222 allows 800mA of collector current & also 652mW of power dissipation which can be utilized for driving larger loads as compared toBC547.
- So, the 2N2222 transistor is the best choice for switching high current loads.
- This kind of transistor is mainly used for amplifying current.
- This transistor can be used as a switch to automatically switch ON/OFF any appliances.
- It is used for PWM due to its quick response.
- Because of its fast response time, it can be used for pulse width modulation.
- It is typically used in automation & embedded projects.
- Audio Preamplifiers.
- Sensor Circuits.
- Audio Amplifier Stages.
- Used to switch several loads simultaneously.
- RF Circuits.
- Darlington Pairs.
- These transistors are used in Motor drive circuits like VFD or variable frequency drives.
- Used in Rectifier Circuits & DC Inverters.
- It is used as an amplifier to amplify voltage, current & power.
- Darlington pair transistors are used for attaining the maximum current from the emitter terminal to the collector.