Posts tagged transistor
Im studying the equivalent model of a BJT common emitter amplifier at high frequencies.At university we tought that the BJT at high frequencies looks something like this: However when designing ...
We identify semiconducting electrical components this way: The first digit represents the number of pn junctions inside the semiconducting device The two or more digit number starting at position...
I am calculating the base current of transistor Q1. To simplify the circuit equations, I applied the Thévenin's theorem twice and converted V1 and R1, R2 into Vth and Rth as shown in the image. Vt...
I am trying to analyse what is controlling the load current in the below Darlington configuration. Is it the base current of transistor Q3 which is controlling current through R14 / emitter curr...
A while ago I made a question about the monostable multivibrator .Lets get a picture of it: When switch is closed it enters its unstable state and it eventually returns to the stable state Howe...
In all descriptions of how (non-FET) transistors work I've seen, there is an inherent symmetry: There's either an n-doped layer between two p-doped, or a p-doped between two n-doped, and the descri...
What is your best suggestion for building a follower that would ideally satisfy the following spec: frequency: from 100 Hz (or lower) to 1 GHz input signal impedance: 1 Mohm input signal ampli...
My question is trying to understand if there is an effect on the switching time, on both turn-on and turn-off, between the following configurations. A mirror set up to switch a current, and there ...
Usually, voltage followers are built with bipolar transistors (or with opamps if better precision is needed). In this case, the simple rule says that the transistor emitter "follows" the input vol...
As I have learned, it is allowed to ask a question here to which I already know one of several possible answers. Introduction: In some books and other technical papers (also from universities) it i...
I see a lot of common collector amplifiers with the output taken across an emitter resistor. What is the purpose of doing it this way instead of connecting your load directly to the emitter? I shou...
I understand that some applications require NPN-PNP pairs with identical electrical characteristics. But I would like to understand why.
Why does the Darlington or Sziklai configurations need complementary transistors? For these configurations, when should I use complementary pairs and when could I use not complementary pairs ?
