# Digital Integrated Circuits

#### Ryan$Joined Dec 14, 2018 178 Hi guys I've already faced a problem in Software Programming which how "deleting/updating" data is going on PC, So I decided to learn by myself the switches {0,1} and how they work on PC .. anyone can advice me a good online book to read?! thanks guys #### WBahn Joined Mar 31, 2012 26,398 There are LOTS of online references that explain how MOSFET transistors work. These range from highly quantitative descriptions involving quantum mechanics and doping profiles and whatnot, to very qualitative descriptions aimed at middle school students that just aim to get the gist across, to everything in between. For your purposes, focus on sites that deal primarily with MOSFET transistors operating as a switch. The basic concept is that you have region of the transistor, the channel, that can either be very high resistance (switch is "off") or relatively low resistance (switch is "on"). The channel connects the "drain" to the "source" of the transistor. Whether the channel is "on" or "off" depends on the voltage applied to the "gate" above the channel. In an N-type enchancement mode FET (NFET), a high voltage (relative to the source terminal) turns the channel "on", which in a P-type FET (PFET) the a low voltage turns it "on". CMOS basically works by arranging these FET transistor switches in such a way that a logic signal turns on some transistors and turns off others, the net result generally being that the output pin is connected, via these switches, either to the positive supply or the negative supply at any given time. Beyond that, start working through NAND-to-Tetris. Thread Starter #### Ryan$

Joined Dec 14, 2018
178
thanks! I totally believe in the concept .. but need to learn more about switches ..

#### MrChips

Joined Oct 2, 2009
24,140
What is your concept of a switch?

#### Ryan$Joined Dec 14, 2018 178 What is your concept of a switch? transistor, it's interesting a lil to figure and learn about it #### MrChips Joined Oct 2, 2009 24,140 This would be my concept of a switch: or this: Thread Starter #### Ryan$

Joined Dec 14, 2018
178
May I ask over here my another question? will not post a thread for it.

if I have an inverter which Vin is like what's appeared on the photo down, my question is what happened at edges?! meaning "while getting vin on edges" what happened to "vout"? I may miss understanding the definition of edges.. !
for instance lets assume I have 1 until I arrive to edge so inverter will output 0 till I arrive to edge in vin, so what will be vout at that edge over inverter?!

thanks

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#### Ryan$Joined Dec 14, 2018 178 May I must discard from edges and consider them as nullity at electronics? #### MrChips Joined Oct 2, 2009 24,140 What is your definition of an edge? #### atferrari Joined Jan 6, 2004 4,424 May I ask over here my another question? will not post a thread for it. Please oh please, do not refrain yourself. You have already published so many of a wide variety, so, who cares of one more? #### Norfindel Joined Mar 6, 2008 326 I don't get what you mean with «"while getting vin on edges" what happened to "vout"». That phrase don't make a lot of sense to me. Also, if you post a schematic of the circuit, and clearly state what you don't understand, someone will be able to help you. Thread Starter #### Ryan$

Joined Dec 14, 2018
178
What is your definition of an edge?
I don't know exactly what's edge (frankly) but I meant with it like this:
Code:
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between the upper line and the beneath line there's an edge, a "disconnect" , so how inverter calculate that "disconnect" ?! thanks.

#### Ryan$Joined Dec 14, 2018 178 I don't get what you mean with «"while getting vin on edges" what happened to "vout"». That phrase don't make a lot of sense to me. Also, if you post a schematic of the circuit, and clearly state what you don't understand, someone will be able to help you. the edge is "disconnect" in vin to change/switch case from 1 to 0 .. see my last comment to figure out(I've explained it by two lines) Thread Starter #### Ryan$

Joined Dec 14, 2018
178
To elaborate more to you guys :
I'm attaching here a photo which at V/2 there's an edge (because of disconnect cases), vin was 1 and then switched to 0, "switched" is converted to an edge (disconnect) so how the inverter deals with the edge? or actually do I care for edge? or just consider them as nullity?! thanks

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#### MrChips

Joined Oct 2, 2009
24,140
Therein lies your problem. Your concept of an edge is flawed.
There is no "disconnect". There is never a "disconnect"..
You cannot get from point-A to point-B in zero time.
You must reconsider how you approach problems in electronics. There is no magic in the real world.
Every behaviour has real explanations and can be understood by applying real-world experiences.

#### Norfindel

Joined Mar 6, 2008
326
The inverter switches it's output from 1 to 0, in response from the input signal going from 0 to 1. That's the ideal behaviour. In reality, it takes a small time to switch states, and the voltage don't go instantly from 5v to 0v, but it falls really fast.
Generally, you don't need to be concerned about that.