# Search results

1. ### Meaning of Sigma in Laplace transform

I am really looking for the answers to this question. Hope someone could make it clear.
2. ### I How inversion layer shields electric field?

This question is somewhat relating to electronics but I think it fits better with physics. The leccture here (slide 13) shows that the gate to body capacitance (Cgb) in linear region is 0. However, there is no explanation at all. I tried to find the explanation from the reference book and got...
3. ### A Fixed effective charge in flat band voltage

I am having a hard time understanding flat band voltage in MOS capacitor. Please see the picture below about MOS capacitor. Q0 is a fixed effective charge at the surface between oxide and semiconductor and it is positive here. The voltage across the oxide caused by the fixed charge ψox =...
4. ### Archived The drift and diffusion currents under equilibrium

Thank you! Could you explain about unrealistic phenomenon here? Why is there a charge accumulation? I don't see how is each side of equation 2.61 can be zero. For the right hand side part, the total current always flows from p to n and in the left hand side the total current always flows from p...
5. ### Why LC tank only oscillates at resonant frequency?

I simulated the oscillator. If Vdd is step voltage then the oscillator oscillates but if Vdd is constant then it doesn't oscillate. Could you explain why?
6. ### Why LC tank only oscillates at resonant frequency?

Hi, the resistances are same (not exactly because tolerance)
7. ### Why LC tank only oscillates at resonant frequency?

Thanks for the detailed answer. I have some problems understanding the oscillator. The first one relating to the boldfaced part above. I don't get what you meant here. Second problem is that how can the oscillation start up? Two transistors are exactly the same, so which one will be ON first...
8. ### Why LC tank only oscillates at resonant frequency?

Hi, I read that that circuit can be converted to LC tank circuit using negative resistance of these mos transistors. So I think they are equivalent.
9. ### Why LC tank only oscillates at resonant frequency?

So, could you explain why this cross coupled oscillator below oscillate? It is only connected with a DC voltage source.
10. ### Why LC tank only oscillates at resonant frequency?

Thanks a lot! I have one more question. Assume I have an ideal parallel LC and it is connected permanently with an ideal constant voltage source. Does the LC tank oscillate with a sinusoidal waveform? I am confused because it is connected with a constant voltage source?
11. ### Why LC tank only oscillates at resonant frequency?

I am wondering why LC tank only oscillates at resonant frequency not other frequencies? Is there a physics explanation for that?
12. ### Confusion about a point and a line

Yes, I searched a lot but still feel confused. I am doing some integrals and really curious. That makes sense. Is there an direct explanation to this even philosophy?
13. ### Confusion about a point and a line

A point has no dimension and a line, which has dimension, is made from points together. How does something without dimension create something with dimension? I can't really make any sense of it. Could you share your opinions?
14. ### Conditions for Laplace and its inverse transform to exist

Thank you, SteamKing and AlephZero. SteamKing: I didn't express it clearly. My question is why in circuit analysis using Laplace (for example, the analysis given in the link), the author didn't consider about the existence of Laplace Transform and Inverse Laplace Transform before applying to...
15. ### Conditions for Laplace and its inverse transform to exist

Sorry for the link. I don't know why it doesn't work when I click in that link directly. Could you go to the first result in Google below? https://www.google.com.vn/#q=http:%2F%2Fpeople.seas.harvard.edu%2F~jones%2Fes154%2Flectures%2Flecture_0%2FLaplace%2Flaplace.html Here is the pdf version...
16. ### Conditions for Laplace and its inverse transform to exist

Thank you. For example, in the RLC circuit from this page below, how could you know that Laplace transform and its inverse transform exist before using them? In that example, I see that the author used Laplace and inverse transforms without considering the conditions for these transforms to...
17. ### Conditions for Laplace and its inverse transform to exist

I usually see that Laplace transform is used a lot in circuit analysis. I am wondering why can we know for sure that the Laplace and its inverse transform always exists in these cases. Thank you.
18. ### Why can't energy change abruptly?

Now, I just read that the voltage across an ideal inductor and the current through an ideal capacitor can change abruptly.
19. ### Can diffusion exist in this case?

Could anyone help?
20. ### What is the difference in mechanisms in which IB1 and IB2 are formed?

iB1: holes in Base move from Base to Emitter This is same as electrons from emitter, recombining with holes in Base to become valance electrons and they continue move to B. iB2: electrons from emitters recombining with holes in Base and continue move to B I don't see any difference. Please help.
21. ### Can anyone tell me how the hole will move after this?

I would like to ask some more questions. In pure semiconductor, thermal energy will create electron-hole pairs all the time. If there is not recombination ( I mean electrons go from conduction band to valance band) then the current will continue forever and the pure semiconductor will become a...
22. ### Boost-Flyback converter

I am reading about Boost-Flyback converter and this is a bit confusing. Could you explain the role of D1 and C1 here? The lecture says that "D1 and C1deliver to the output the energy stored in the transformer leakage inductance Ld." I can't understand what is meant here. And could you explain...
23. ### Approximation formula proof

Thank you all. I think you misread the question a bit. The expression on the right hand side of the equation is e^{-\frac{t}{τ}} with τ = τ_1 + τ_2.
24. ### Shared contacted diffusion in layout

Thank you. I am learning about analog design. Hope you could help!
25. ### Output states of a CMOS gate

Thank you. That was a bit confusing.
26. ### Shared contacted diffusion in layout

I am confused about shared contacted diffusion in CMOS layout. Is it possible to use shared contacted diffusion for two nMOS transistors with different widths? BTW, two nMOS and pMOS transistors are never shared contacted diffusion, right?