The 2N2222 transistor is a commonly used NPN bipolar junction transistor (BJT) for general low power amplification or switching applications. It is designed for low to medium current, low power, medium voltage and can operate at moderate speeds. 2N2222 is considered to be a very common transistor and is used as an example of an NPN transistor. It is often used as a small signal transistor, and it is still a small general-purpose transistor that lasts for a long time.
What is 2N222 NPN Transistor
The 2N2222A is an NPN transistor, so when the base pin is grounded, the collector and emitter will remain off (reverse biased); when the base pin is signaled, the collector and emitter will be closed (positive Offset). The gain value of the 2N2222A is 110 to 800, which determines the amplification capability of the transistor. The maximum current flowing through the collector pins is 800mA, so we can’t use this transistor to connect loads that consume more than 800mA. In order to bias the transistor, we must supply current to the base pin, which should be limited to 5 mA.
When the transistor is fully biased, it can allow a maximum of 800mA to flow through the collector and emitter. This phase is called the saturation region and the typical voltages allowed across the collector-emitter (V CE) or base-emitter (V BE) are 200 and 900 mV, respectively. When the base current is removed, the transistor is completely turned off. Known as the cut-off region, the base emitter voltage may be approximately 660 mV.
|Pin Number||Pin Name||Description|
|1||Emitter||Current Drains out through emitter|
|2||Base||Controls the biasing of transistor|
|3||Collector||Current flows in through collector|
- Bi-Polar high current NPN Transistor
- DC Current Gain (hFE) is 100
- Continuous Collector current (IC) is 800mA
- Emitter Base Voltage (VBE) is 6V
- Collector Emitter Voltage (VCE) is 30V
- Base Current(IB) is 5mA maximum
- Available in To-92 Package
- 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.
How to read 2N222 transistor
The transistor is made of a semiconductor such as silicon or germanium. They consist of three or more terminals. They can be considered as electronic valves because a small signal sent through the intermediate terminal controls the current flowing through the other terminals. They mainly function as switches and amplifiers. Bipolar transistors are the most popular type. They have three layers, each with a wire. The middle layer is the base and the other two layers are called the emitter and collector. The technical information of the transistors can be found on their packaging, on the manufacturer’s data sheet, and in some electronic textbooks or manuals. They contain information about transistor characteristics and operation. The most important are gain, dissipation and maximum rating. Find a general description of a transistor that contains information about how to use a transistor in a circuit. Its function will be described as zooming in, switching, or both.
The value of this resistor can be calculated using the following formula: R B = V BE / I B
- Observe the loss rating of the device. This parameter tells the transistor how much power can be safely handled without damage. Transistors are often described as power or small signals, depending on the rating. Power transistors typically dissipate one watt or more of power, while small signal transistors dissipate less than one watt of power. The 2N222 has a maximum dissipation of 350 milliwatts (milliwatts) and is therefore classified as a small signal.
- Study the current gain parameter hfe. It is defined as a gain because a small signal at the base produces a much larger signal at the collector. The HFE has a minimum and a maximum, although neither is listed. The 2H3904 has a minimum HFE of 100. As an example of its usage, consider the collector current formula icollector=hfe\u ibase. If the base current IBase is 2 mA, the equation specifies that the minimum current at the collector is 100 mA = 200 mA (mA). Hfe can also be called β(dc).
- Check the parameters of the maximum breakdown voltage. The breakdown voltage is where the transistor stops working or is destroyed if it is given such a large input voltage. It is not recommended to have transistors work near these values to avoid shortening their lifetime. VCB is the voltage between the collector and the base. Vceo is the voltage between the collector and the emitter when the base is open, and veb is the voltage from the emitter to the base. The VCB breakdown voltage of the 2N3904 is listed as 60V. The remaining value of VCEO is 40V, and the remaining value of VEB is 6V. These are the amounts that should be avoided in practice.
- Check the maximum rated current. The IC is the maximum current that the collector can handle. For 2N222, this is listed as 200 mA. Note that these ratings assume an ideal temperature that is specified or assumed to be room temperature. This usually does not exceed 25 degrees Celsius.
- Summarize the data. For some 2N222 transistors with a collector current of less than 200 mA at room temperature and not exceeding the rated power, the gain will be as low as 100 or as high as 300. However, most 2N222 transistors have a gain of 200.