BC547 VS 2N2222 Understanding the Difference

If you are looking for BC547 VS 2N2222 then you have come to the right page.  Both of the transistors are very famous and they are widely used in commercial equipment and appliances and also used by electronics students, tinkerers and hobbyists. You will find thousands of circuits on the internet and also in books that use these transistors. Both of the transistors are general purpose type, good quality, reliable, low cost, and can easily be found in any electronic store. In this post, we are going to compare these two transistors and understand the main differences between these transistors, what conditions we can use them interchangeably, and other useful info. In the end, we will also answer some frequently asked questions. Also, note that 2N2222 is also manufactured in a TO-18 metal can package but in this post we are discussing about the TO-92 package which is the plastic package transistor.

BC547 VS 2N2222 Pin Difference

By looking at the above pin comparison image above we can understand that pin configuration of both the transistors are different. BC547 transistor’s first pin is collector, second is base and third is Emitter while the 2N2222 transistor’s first pin is emitter, second is base and third is Collector. So whenever we are replacing them we have the change the face in opposite side because the Collector and Emitter pins of the transistors are opposite to each other.

Ratings & Characteristics Comparison:

Can We Use BC547 Instead of 2N2222

To understand this first we will compare the ratings and characteristics of these transistors. In the above table, you can see that the BC547 collector to emitter voltage is 50V, collector current is 100mA, Total device dissipation is 500mW, DC current gain is 110 to 800, and transition frequency is 300MHz. And the 2N2222 collector to emitter voltage is 40V, the collector current is 600mA, Total device dissipation is 625mW, DC current gain is 30 to 300, and transition frequency is 250MHz.

As you know that a transistor is used for switching, amplification, oscillation etc. in the electronic circuits. So if you want to use the BC547 in place of 2N2222 then it is important to check for what purpose the 2N2222 is used in that particular circuit whether it is used as a switch, amplifier, oscillator, or else. If it is used for any other purpose than a switch then you can easily replace it with BC547 because there is not much difference between the two according to these conditions. Moreover, if you are replacing it in amplification or preamplification circuits then BC547 will perform a little bit better than the 2N2222 because it has more DC current gain and also more low noise capabilities than 2N2222.

But if it is used as a switch then you cannot directly replace them without knowing how much load current the 2N2222 is driving in the circuit because there is a huge difference between the collector current of both transistors. So first of all check how much current that load requires this can be checked by using a digital multimeter on ampere settings and placing the test leads between the transistor and the load. You can also find many videos on Youtube on how to check the current. Another procedure to check how much current the load is driving is to check the datasheet of that particular component for example if it is an LED, relay or any other component. So if the load that component requires is under 100mA which is the total collector current of BC547 then you can easily use it instead of 2N2222 but if it’s more than that then you have to find another replacement for 2N2222.

Can We Use 2N2222 Instead of BC547

2N2222 can be used instead of BC547 in any condition and also you don’t have to check anything because if it is used as a switch then 2N2222 has a higher collector current than BC547 so it will work smoothly and if it is used as an amplifier or any other purpose then 2N2222 will also work in these conditions too.

Conclusion

So you cannot use BC547 in the place of 2N2222 when it is used as a switch until you don’t know how much load the 2N2222 is driving but other than the switch you can use BC547 in the place of 2N2222 without any problem. But if you want to use 2N2222 in place of BC547 then you can use it in all conditions. Also keep in mind that BC547 have better features than 2N2222 when it comes to amplification so in some cases you may notice some minor differences for example if you are using it in a preamplifier circuit.

FAQs

What is a 2N2222 transistor used for?

2N2222 is a general purpose BJT transistor, it is made to use in a variety of general purpose applications in an electronic circuit such as switching, amplification, preamplification, oscillator.

What can I use instead of BC547?

There are many transistors you can use instead of BC547 which are 2N3904, 2N4401, etc. Further details about that can be found on the BC547 page.

What is a Bc547 transistor used for?

BC547 is also a general purpose BJT transistor, designed to use in a variety of general purpose applications in electronic circuits such as switching, amplification, preamplification, oscillator.

What can I use instead of 2N2222?

There are several equivalents of 2N2222 or the transistors you can use instead of 2N2222 such as 2N1613, 2N2218 etc. For further details on that visit the 2N2222 page.