All Questions
Tagged with semiconductors transistors
118
questions
16
votes
3
answers
8k
views
Can a thyristor be built from two transistors?
Supposedly, an SCR/thyristor is just a simple, four layer PNPN semiconductor.
If that's the case..
When a circuit calls for a SCR/thyristor, and there isn't one available, can it be substituted by (...
- 1,089
14
votes
1
answer
8k
views
Where are the depletion PMOS transistors?
In school, I was taught about PMOS and NMOS transistors, and about enhancement- and depletion-mode transistors. Here's the short version of what I understand:
Enhancement means that the channel is ...
- 17.6k
13
votes
2
answers
2k
views
Why are BJTs more reliable than MOSFETs under severe weather conditions?
I read in a textbook (Microelectronic Circuits by Sedra and Smith, pg. 494, (2010) sixth edition) that BJTs are preferred by the automotive industry due to their reliability under severe weather ...
- 352
12
votes
4
answers
18k
views
Why can current flow through the reverse biased base-collector junction (N-P junction) in a BJT with a forward biased base-emitter junction?
If the base-emitter junction of a BJT is forward biased, then current can flow through the reverse biased base-collector junction (N-P junction). This disagrees with my understanding of the PN ...
- 1,655
6
votes
4
answers
949
views
In a JFET, is the gate *always* connected to the bulk/substrate?
In a JFET, is the gate always connected to the bulk/substrate ?
Or is there "no rule" (sometimes it is, sometimes it is not)?
And what about the case of the MOSFET ?
6
votes
1
answer
163
views
MOSFET switching on
I have a doubt. Consider an N-MOSFET: which is the voltage that can switch on it? The voltage between Gate and? Sometimes I read "between Gate and Bulk", sometimes "between Gate and Source", sometimes ...
- 3,550
6
votes
1
answer
303
views
How point-contact transistor work?
In December 1947 Bardeen, Brattain and Shockey introduced a device which is considered to be the first transistor. This transistor was point-contact device. So, it used metal-semiconductor junctions.
...
- 113
6
votes
2
answers
25k
views
Working of miniature Tesla coil?
Can anyone explain the given circuit.
I seem to have done it and its perfectly working. But can someone explain the principle/theory and working behind this circuit from when the switch is turned on..
...
- 63
5
votes
6
answers
430
views
is any other technology than semiconductor transistors or vacuum tubes that can be used as active devices?
I am curious to know if one can amplify a signal or make nonlinear active distortion to an electric signal without semiconductor transistor or vacuum tube technologies?
- 231
5
votes
3
answers
2k
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BJT: definition of "edge of saturation"
The book Sedra/Smith (Microelectronic circuits) tells in chapter 5 the following:
My question: I found no statement on why the EOS is defined by the point where vc < (vb - 0.4V).
Seems like other ...
- 1,041
5
votes
2
answers
3k
views
Are BJTs used in modern integrated circuits to the same extent as MOSFETs?
On modern integrated circuits, are there as much BJT's on the chip as MOSFET transistor? If not, why?
- 377
5
votes
1
answer
2k
views
Some questions on NPN transistor [closed]
The beauty of transistor structure lies in its different areas of each of the layers. Also, the base layer is kept between collector and emitter. We can say that the base acts just like a ‘door’ for ...
- 163
5
votes
1
answer
1k
views
NPN is physically symmetrical yet the model isn't? [duplicate]
It just strikes me as very odd that all representations of the actual physics of NPN transistors in textbooks is perfectly symmetrical, yet neither the diagram used to represent them nor the ...
- 787
4
votes
4
answers
1k
views
Relation between collector current and Vce voltage in saturation mode
I have confusion regarding how collector current affects the voltage across collector to emitter in NPN transistor (2N4123).
How do I interpret this graph? Can I say when collector current increases ...
- 306
4
votes
3
answers
640
views
Need to increase the amplitude of op-amp output
I'm using this circuit to measure the RPM of a DISC rotating at 24000 rpm. This circuit is working fine. But the problem is with amplitude. It should be of 4.2V, but actually is of 2V as shown in ...
- 903