# Recent content by anhnha

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...