BC549: similar to BC548 but with low noise for somewhat more critical applications or sensitive to electronic noise.But each one has been optimized for a specific type of task: The encapsulation of all is the same, the SOT54 or TO-92. That said, if we focus on family, the differences between all the members it is quite mild.

That is, a semiconductor doped with an element of the periodic table that allows it to have an excess of charge carriers (electrons) for the N parts, and a semiconductor doped with an element with fewer valence electrons giving rise to a P-type semiconductor with an excess of positive charge carriers in this case (holes). In the case of BC547 we have already said that it is an NPN. The name of bipolar comes from the fact that they form 2 PN junctions, since transistors have three semiconductor layers arranged in two possible ways: NPN and PNP. These types of bipolar transistors are made of materials such as germanium, silicon or gallium arsenide. That is, they are not field effect transistors like FETs, light-controlled phototransistors, etc. They are all of the bipolar or bipolar junction type (BJT for Bipolar Junction Transistor). The BC547 belongs to the family of transistors with similar characteristics as the BC546, BC548, BC549 and BC550. There are also other designations such as the BF, but in this case it is used to identify the transistors used for RF (radio frequency), that is, those that achieve good gains at very high frequencies. In addition, for its acronym BC It shows that it is a silicon transistor (B), for low frequency (C). The differences between the series were basically encapsulated, being the same inside. And it evolved from BC108, BC238, to what we now know as BC548 with an encapsulation cheaper type TO-92, and from here came variants such as the BC547. Later it would have a new plastic package and renamed with the code BC148. That package was considerably more expensive than the plastic equivalent TO-92, but the heat dissipation is better in the former. Initially it was named with the BC108 nomenclature and had a TO-18 type metal encapsulation (Transistor Outline package - case style 18 ). It is a bipolar junction transistor that was originally developed by Philips and Mullard between 19. If you are a maker, you like DIY and electronics, surely you have ever needed to use a BC547 transistor.

Bc547 transistor download