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2N4427 Transistor Data
Key transistor data for the 2N4427 RF power transistor including key electrical parameters, pinout, package type and many other key transistor datasheet details.
The 2N4427 is described as a silicon NPN overlay transistor, designed for VHF and UHF equipment.
Applications include amplifier; pre-driver, driver, and output stages. Also suitable for oscillator and frequency-multiplier functions.
Key details and performance parameters for the 2N4427 transistor.
| Transistor parameters & data |
|
|---|---|
| Parameters | Details |
| Transistor type | NPN silicon RF power transistor |
| Package type | TO39 |
| VCBO max (V) | 40 |
| VCEO max (V) | 20 |
| VEBOmax (V) | 2 |
| VCEsat (V) | 0.5V @ I |
| IC max (mA) | 400 |
| TJ Max °C | |
| PTOT W | 1 |
| fT min (MHz) | 500 |
| COB | 4pF |
| hfe | 10 - 200 |
| IC for hfe | 100 mA |
| Similar / equivalents | |
Outline:
Pinout:
Explanation of transistor parameters
| Parameter | Explanation |
|---|---|
| VCBO Max | Maximum collector-base voltage with emitter open circuit . |
| VCEO Max | Maximum collector-emitter voltage with base open circuit. |
| VEBO Max | Maximum emitter-base voltage with collector open circuit. |
| VCEsat (included where applicable) | The voltage drop across the collector-emitter when the transistor is fully saturated (acting as a closed switch). |
| IC Max | Maximum collector current. |
| Parameter | Explanation |
|---|---|
| TJ | Maximum junction temperature. |
| PTOT Max | Maximum device dissipation normally in free air at 25°C unless other conditions indicated. |
| fT Min | Minimum cutoff frequency at which the current gain in a common emitter circuit falls to unity. |
| COB Max | Maximum collector capacitane, normally measured with emitter open circuit. |
| hFE | DC current gain for HFE at IC. [Note hfe is the small signal gain and although this may be slightly different, the transistor current gain will vary considerably from ne transistor to the next of the same type.] |
| PTOT Max | Maximum device dissipation normally in free air at 25°C unless other conditions indicated. |
These are the main transistor parameters that have been included in our list. There are others, but these help quantify the main elements of the performance of the transistor.
Please note, that the data given is the best estimate we can give within a tabulated summary of this nature. Parameters also vary between manufacturers. Electronics Notes cannot accept any responsibility for errors, inaccuracies, etc, although we do endevaour to ensure the data is as accurate as possible.
Notes and supplementary information
• Availability & sources
The device is available from a number of stockists and electronic component distributors.
• Typical performance
The 2N4427 offers a minimum power gain of around 10dB for 0.1 watt input with a collector VCE of 12VDC and at 175 MHz.
Under the same conditions it should give an output power of around 1 Watt minimum and with a 45% efficiency level.
It is worth noting that the collector is connected to the metal case. This gives good thermal conduction away from the collector region where the majority of the heat is generated, but case must be taken not to short circuit it in any equipment.
• Manufacturers
The 2N4427 has been manufactured by a variety of companies including Philips Semiconductor, RCA, Advanced Power Technology RF, and others.
Now it is marked as an obsolete component by many component distributors and this means that sourcing it new might be an issue, and it should not be considered for any new designs.
Written by Ian Poole .
Experienced electronics engineer and author.
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