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| srce:
--- Quote from: ZeroResistance on October 19, 2018, 01:41:03 pm ---What's the purpose of the fingers. What n=2 did what connect the 2 drains together and also the gates together and also the sources together. So in effect created 2 transistors in parallel? Correct? --- End quote --- Yep. But you'll notice the W is split between them. i.e. each finger has W' = W/n --- Quote from: ZeroResistance on October 19, 2018, 01:41:03 pm ---Same would have been the case with m=2 right?. --- End quote --- No, you'd get two separate transistors each with W'=W. Also their drains would not be shared, so they'd have a larger total area. There's a lot of other parameters to play with too :P (And then different transistor types too - different threshold voltages / oxide thickness etc - 36 different ones in this process!). |
| ZeroResistance:
Still trying to wrap my head around "At the lowest level everything is analog" And how so? I guess you can use a transistor either in saturation mode or in linear mode. So should'nt it boil down to the operating mode of the tranistor? |
| Wimberleytech:
--- Quote from: ZeroResistance on October 20, 2018, 09:11:13 am ---Still trying to wrap my head around "At the lowest level everything is analog" And how so? I guess you can use a transistor either in saturation mode or in linear mode. So should'nt it boil down to the operating mode of the tranistor? --- End quote --- If you open your eyes only at midnight and at noon, the sun gives you two intensities (0 and 1). If you keep your eyes open continuously, the sun's intensity gradually increases to its peak and then gradually decreases to its minimum. The first case is digital while the second is analog--it is all a matter of your sample rate. An inverter is a digital gate. It outputs two logic levels: 0 and 1 ONLY IF you sample it such that you NEVER see the transitions from 0 to 1 and 1 to 0. During those transitions, one can say that the signal is analog. The IEEE dictionary defines analog as "continuous" whereas digital is "discrete" (my paraphrase). If you look close enough...everything is analog (everything above quantum level, that is). |
| coppice:
--- Quote from: ZeroResistance on October 20, 2018, 09:11:13 am ---Still trying to wrap my head around "At the lowest level everything is analog" And how so? I guess you can use a transistor either in saturation mode or in linear mode. So should'nt it boil down to the operating mode of the tranistor? --- End quote --- You say "saturation mode" like its a clean digital state, when in fact its just as analogue as the linear region. How hard you push things into saturation affects how much energy gets stored, and has to be removed to get the thing out of saturation. For high digital performance, saturation has to be well controlled. Unless you get down to something which functions by a single molecular flip, I don't see how anything being used for digital purposes at the macro level is not built on an underlying analogue scheme. |
| srce:
It's all analog until you get to the quantum level. Then it turns out everything is digital. :P |
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