What is a transistor 2N3904?
Transistor 2N3904 Which is called the transistor 3904 AR is for NPN class transistor Hence the collector and emitter will be left open (i.e. reversely biased) when the base terminal of the base is fixed to the ground, and will be closed (i.e. forward biased) when a signal is provided on the base terminal of the transistor. 2N3904. This transistor has a Gain gain Up to 300, this value determines the amplification amplitude of the transistor. The maximum amount of current that can flow through the collector terminal is 200 mA, and therefore we cannot connect loads that consume more than 200 mA using this transistor. To bias the transistor we have to supply current to the base terminal, this current must be limited (IB) at 0.5 mA.
When this transistor is completely biased, it can allow a maximum of 200 mA of electrical current to flow through the collector and emitter. This phase is called the saturation region, and it can be the typical permissible voltage across the collector-emitter (VCE) Or emitter-base (VBE) E , 40 and 60 volts, respectively. When the base current is removed, the transistor becomes completely switched off.This phase is called the Cut-off-Region. And the base emitter voltage can be around 600 mV.
The following figure shows the leg numbers of the terminals with the designation and arrangement of this transistor
The following table describes the description and function of each terminal of the transistor 3904
Party number | Party name | the description |
1 | Emitter Emitter | The current is drained through the emitter to the GND earth . |
2 | Al - Qaeda Base | It controls transistor bias. |
3 | The Collector | Current flows through the collector towards the electrical load to be run. |
Features and specifications of the transistor 2N3904
- Class NPN bipolar transistor.
- DC gain value (hFE) is 300 max.
- Continuous collector current (IC) is 200 mA.
- Base-emitter voltage (VBE) is 6 volts.
- Collector-emitter voltage (VCE) is 40 volts
- Collector base effort (VCB) is 60 volts
- Available in the To-92 package .
Note: Full technical details can be found in the data sheet at the end of this page.
Transistor functions 2N3904
Transistor 2N3904 As an electrical switch
When a transistor is used as a switch, it is turned on in the saturation and cutoff region which we mentioned earlier and discussed, the transistor will act as an open switch during forward bias and as a closed switch during reverse bias, this bias can be achieved by supplying the required amount of current to the pin or terminal of the base. As mentioned, the bias current should be at a maximum of 5 mA. Any value over and above 5 mA will damage and destroy the transistor; So a resistance is always added in series with the base tip. The value of this electrical resistance can be calculated (RB) using the following formula below
RB = VBE / IB
Where the value of VBE should be 5 volts for the transistor 2N3904 And the base current value ( IB current depends On the stream of the collector (IC)) The value should not exceed 5 mA.
Transistor 2N3904 As an amplifier
Transistors act as an amplifier when operating in the Active Region. This transistor can amplify power, voltage, and current in various configurations (combinations).
Some of the configurations used in amplifier circuits or amplifiers are:
- A common emitter amplifier Common emitter amplifier
- Common collector amplifier Common collector amplifier
- Sound Blaster Joint Common base amplifier
One of the most important types mentioned above is the common emitter type, which is the common and often used configuration. When used as an amplifier, the DC gain of a transistor can be calculated using the formulas below
DC Current Gain = Collector Current (IC) / Base Current (IB)
Where IB Is the current at the base.
IC It is the stream of the collector.
DC Current Gain: DC gain value.
Applications and uses of the transistor 2N3904
- Drivers, such as Relay Driver, Drive of LED LED Driver And others.
- Speaker units like subwoofers, signal amplifier etc..
- Since the value of both VCB And VBE Are high, so they can be used to control voltage loads of up to 40V.
- Commonly used in television and other home appliances.
Transistor variants and equivalents 2N3904
There are many NPN alternatives and equivalents Which can replace the transistor 2N3904 It is as follows:
BC549 , BC636 , BC639 , 2 N2222 TO-92 , 2 N2222 TO-18 , 2 N2369 , 2 N3055 , 2 N3906 , 2 SC5200.
Numéro de série | Type | Equivalent | Description |
2N3904 |
| MMBT3904 Diodes | sot23, 40 Vce, 0.2 A Ic, 300 MHz Ft, |
2N3904 On Semiconductor |
| BSS84P Infineon Technologie ... | |
2N3904 NEC Electronics |
| IPP80N04S2-H4 Infineon Technologie ... | |
2N3904 National Semiconduct ... |
| TLE4274GS V33 Infineon Technologie ... | |
2N3904 Fairchild Semiconduc ... |
| TTC4116FU Toshiba Semiconducto ... | IC = 0.15A |
2N3904 |
| 121-972 | |
2N3904 |
| 14-805-12 | |
2N3904 |
| 2N3564 | |
2N3904 |
| 2N440 | |
2N3904 |
| 2N5088 | |
2N3904 |
| 2N5089 | |
2N3904 |
| 2N5210 | |
2N3904 |
| A5T3904 | |
2N3904 |
| ECG123A |