2N2222
JEDEC Part Number = 2N + [Digits decoded from color bands]
DETAILED SPECIFICATIONS
Substrate / Material
Silicon Active Substrate
Semiconductor Application
General Purpose switching
Coding Standard
JEDEC (EIA-359)
Input Parameters Specification
implied JEDEC PrefixThe static '2N' designation is standard for three-lead JEDEC transistors. Color bands only code the numerical digits following this prefix.
First Band (1st Digit)Represents the first significant digit of the transistor's design serial registration identifier.
Second Band (2nd Digit)Decodes the second critical numerical digit of the classic semiconductor part number.
Third / Fourth BandsProvide subsequent trailing digits to map the exact registered component index (e.g., 2N3904 or 2N2222).
Historical Transistor Coding Examples
2N2222 General Purpose NPN
Decoded as 4-Band: Red (2), Red (2), Red (2), Red (2). This classic high-speed switching silicon device translates simply to 2N2222.
2N3904 NPN Amplifier
Decoded as 4-Band: Orange (3), White (9), Black (0), Yellow (4). Found in countless standard industrial switching nodes.
2N109 Germanium Transistor
Decoded as 3-Band: Brown (1), Black (0), White (9). Classic audio output device used in early pocket radio designs.
2N2907 PNP Variant
Decoded as 4-Band: Red (2), White (9), Black (0), Violet (7). Common complementary counterpart to the 2N2222.
Semi-Conductor JEDEC Color Code Diagrams & Theory
During the early days of solid-state electronics, printing sharp, readable text on tiny curved transistor packages (such as classic TO-92 plastic housings or metallic epoxy capsules) was difficult. To overcome this limitation, manufacturers adapted the standard resistor color-coding standard to label transistors.
Under the standardized Joint Electron Device Engineering Council (JEDEC) system, the prefix "2N" represents a three-lead active semiconductor device (such as bipolar junction transistors or field-effect transistors). Therefore, the color bands represent only the remaining numbers of the registration standard. When you view a transistor with three or four color bands, you can read them sequentially from top to bottom (away from the lead wires) to find the numeric sequence.
Formulas & Mathematical Logic
JEDEC Rule: Device Code = "2N" + (Band 1 Digit) + (Band 2 Digit) + (Band 3 Digit) + [Band 4 Digit, if present]
Classic Diodes (Alternative): Standard JEDEC diodes use "1N" prefix, using the same color band digit alignment.
Color Digit mapping follows the global international standard: Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Grey=8, White=9.
Step-by-Step Example
Example: 4-Band Transistor - Orange, White, Black, Yellow
Step 1: Write down the implied base prefix for a transistor: "2N".
Step 2: Note the band digit equivalents: Orange = 3, White = 9, Black = 0, Yellow = 4.
Step 3: Concatenate the sequence: 3, 9, 0, and 4 to form 3904.
Step 4: Combine the components to identify the registered industry part: 2N3904.
How to Use This Calculator
Choose the band count mode (3-Band or 4-Band) to match your vintage component package.
Locate the top band painted furthest from the outgoing physical metal leads. Read downward.
Select the band colors using our selection picker menus.
The matching JEDEC registered transistor model code updates instantly on screen.
About This Calculator
Decode physical semiconductor color codes with speed.
This tool helps engineers, hobbyists, and restorers identify older, hard-to-read transistors marked with standard JEDEC color coding.
Because these color codes are standardized, you do not need to hunt through old manuals to translate faded markings. Simply match the visual bands on our high-contrast layout, and you can instantly identify obsolete Germanium or classic Silicon semiconductors.
Ideal ForVintage radio restoration, component sourcing, and circuit reverse-engineering.
Decodes BandsSupports both 3-band and 4-band JEDEC active components.
Modern GraphicsFeatures a responsive, lightweight CSS representation that adapts to dark and light screens.
Error-Free LogicPrevents invalid code combinations by sticking to standard registered digits.
Tip: Standard transistors are non-symmetrical. If your transistor has a flat side (TO-92), hold it with the flat face pointing toward you and read the bands from top to bottom.
Frequently Asked Questions
1. What does the "2N" prefix on a transistor stand for?
Under JEDEC notation, "2N" denotes a component with two internal active semiconductor junctions, which corresponds to standard three-terminal transistors. Diodes use "1N" (one junction).
2. Why did old transistors use color bands instead of printed text?
Early automated printing machinery struggled to place durable, legible text on small, curved plastic or metal surfaces. Color bands were cheap, highly visible, and did not smudge during assembly.
3. Can I use this calculator for diodes?
Yes, JEDEC diodes follow the same sequence. However, you must swap the "2N" prefix with "1N" (e.g., Brown, Black, Black, Black would represent a 1N1000 diode).
4. Why doesn't my transistor have a multiplier band?
Unlike resistors or inductors, JEDEC transistors are registered by sequential part numbers. Thus, the color bands represent standard, direct integers rather than multipliers or tolerances.
5. What standard is used for JEDEC transistor color codes?
They follow EIA standard color digit mappings, where colors correspond to digits 0 through 9 sequentially from Black to White.
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