Cross section of a 2N2222 in the TO-18 package

The 2N2222 is a common NPN

bipolar junction transistor A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor, uses only one kind of charge carrier. A bipola ...

(BJT) used for general purpose low-power amplifying or switching applications. It is designed for low to medium

current Currents, Current or The Current may refer to: Science and technology * Current (fluid), the flow of a liquid or a gas ** Air current, a flow of air ** Ocean current, a current in the ocean *** Rip current, a kind of water current ** Current (stre ...

, low

power Power most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may a ...

, medium

voltage Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to ...

, and can operate at moderately high speeds. It was originally made in the

TO-18 In electronics, TO-18 is a designation for a style of transistor metal case. The case is more expensive than the similarly sized plastic TO-92 package. The name is from JEDEC, signifying ''Transistor Outline Package, Case Style 18''. Constructi ...

metal can as shown in the picture. The 2N2222 is considered a very common transistor, and is used as an exemplar of an NPN transistor. It is frequently used as a small-signal transistor, and it remains a small general purpose transistor of enduring popularity. The 2N2222 was part of a family of devices described by

Motorola Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorola ...

at a 1962

IRE Ire or IRE may refer to: Ire * Extreme anger; intense fury * Irē, the Livonian name for Mazirbe, Latvia * A town in Oye, Nigeria * ''Ire'' (album), a 2015 album by the Australian metalcore band Parkway Drive * Ire (Iliad), a town mentioned in ...

convention. Since then it has been made by many semiconductor companies, for example,

Texas Instruments Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globa ...

.''The Transistor and Diode Data Book for Design Engineers'', Texas Instruments Incorporated, no date, TI publication number CC413 71242-73-CSS, page 4-93

Specifications

The

JEDEC The JEDEC Solid State Technology Association is an independent semiconductor engineering trade organization and standardization body headquartered in Arlington County, Virginia, United States. JEDEC has over 300 members, including some of the w ...

registration of a device number ensures particular rated values will be met by all parts offered under that number. JEDEC registered parameters include outline dimensions, small-signal current

gain Gain or GAIN may refer to: Science and technology * Gain (electronics), an electronics and signal processing term * Antenna gain * Gain (laser), the amplification involved in laser emission * Gain (projection screens) * Information gain in de ...

, transition frequency, maximum values for voltage withstand, current rating, power dissipation and temperature rating, and others, measured under standard test conditions. Other part numbers will have different parameters. The exact specifications depend on the manufacturer, case type, and variation. Therefore, it is important to refer to the datasheet for the exact part number and manufacturer. All variations have a

beta Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labiod ...

or current gain (h_fe) of at least 100 in optimal conditions. It is used in a variety of analog amplification and switching applications.

Other switching transistors

NPN silicon transistors with similar properties are also made in a variety of small through-hole and surface mount packages including TO-92, SOT-23, and SOT-223. Replacements for the 2N2222 are commonly available in the cheaper TO-92 packaging, where it is known as the PN2222 or P2N2222, which has similar specifications except for the lower maximum collector current. The P2N2222 has a different order of pins than the metal case 2N2222, with its emitter and collector connections switched; other plastic-case transistors also have different pinouts. Single transistors are also available in several different surface mount packages, and a number of manufacturers market surface mount packages that incorporate several 2N2222-type transistors in one package as an array of transistors. The general specifications of the various variants are similar, with the biggest difference being the maximum allowable current and power dissipation. The BC548 family, including the BC547A to BC550C, are lower voltage, lower current, general-purpose transistors in TO-92 packages, originating in Europe, that are often found in small-signal amplification and switching circuits of the type where the 2N2222 might otherwise be used. They are not true replacements, but comparable devices that may be substituted only in circuits where the maximum current and voltage ratings are not exceeded. The 2N2907 is an equally popular PNP transistor complementary to the 2N2222. The 2N3904 is an NPN transistor that can only switch one-third the current of the 2N2222 but has otherwise similar characteristics. The 2N3904 exhibits its forward gain (beta) peak at a lower current than the 2N2222, and is useful in amplifier applications with reduced I_c, e.g., (gain peak at 10 mA for the 2N3904 but 150 mA for the 2N2222). A version of the 2N2222A in a larger metal

TO-39 In electronics, TO-5 is a designation for a standardized metal semiconductor package used for transistors and some integrated circuits. The ''TO'' element stands for "transistor outline" and refers to a series of technical drawings produced by JE ...

case, the 2N2219A had a higher power dissipation rating (3 watts when attached to a heatsink that keeps the case temperature at 25 C, or 0.8 watts in free air, compared with only 1.8 watts and 0.5 watts (respectively) for the 2N2222A.

Part numbers

The 2N2222 (NPN) and 2N2907 (PNP) are complementary transistor pairs. The prefix of each part number varies for each physical package type.

Photo Gallery

References

External links

{{commons category
Datasheet for 2N2222A Hi-reliability equivalent (PDF)
by

Microsemi Microsemi Corporation was an Aliso Viejo, California-based provider of semiconductor and system solutions for aerospace & defense, communications, data center and industrial markets. In February 2018, it was announced that Chandler, Arizona-bas ...

Datasheet for Fairchild Semiconductor's equivalent PN2222 (PDF)

Commercial transistors Bipolar transistors