They only exist in integrated circuits.
OK. Tell us what you think the diodes are doing.
Basically, yes.
There are double gate MOSFETs you can buy.
U is a German symbol for voltage. Can you really be that chauvinistic?There are many NAND circuit diagrams to Google, depending on number of inputs (two is typical, any other would imply an interpretation of which order and what arrived first, since NAND is a binary function).
The "+Us" is not a symbol in my "standard engineering diagram" book (which uses V+), and your diagram does not label if "+Us" is a biased output to Q or if Q pairs with Ground (which, could be labeled in the diagram, isn't, often assumed). There should be a circle on each input, output: but there is not. The symbol apparently meaning ground is not the right symbol for ground.
Instead of being told what inputs and outputs are, we have to read diagram and see OE (whatever that is), I1, I2 (usually currents but not this case) and Q (usually charge, but not in this case) are the ABC->D
The circuit above does NOTHING without specifying the component values - and not all NAND input circuits have the same layout. On this forum it can often be found that "promiscious circuits" are often published which, when assembled even with specified values don't work (ie, because the stated values are not indicative of the tolerance of real components - extra components are then required to adjust). SO - DO WE KNOW if this circuit works?
My main worry about the design is that the base of the NPN transistors, without doing allot of equations to check for sure, could "get zapped". That is, in that design if there is a "wrong state" in the "flops", then higher voltage flows to the base of one of the transistors: there is no clear input chain and output chain, they are mixed, one depends on the other (if one acts wrong, perhaps it burns one or more transistors). I might say "ok, Vout cannot be greater the VbaseMax since the bases aren't isolated from fluctuations", but then I already have circuit values and must insure there are other parts to match it "that can be bought". I then have to consider if Dh Dz are above or below VBaseMax, leading to loop of doing the same thing in that scenario, and I'm stuck in another goose chase.
My other concern is this added "+Us" where we have 2 outputs, one going somewhere unstated, and whether ground is part of the output or if the output is biased output and we are just supposed to know that "somehow, because some school book said everyone knows that". what is U? what is Us? from there i can figure +Us
If I were you and I had a book and teacher resolute to pose me with bogus challenges I'd find something else. My intro to electronic engineering book does exactly this: It introduces engineering layout standards then some circuits. When it gets to logic it gives a simple symbol, the digital chart, simple diagram well labeled, discussion on how it all works without silly questions about what if i add another input can i move a diode around: AND MOVES ON TO OTHER IMPORTANT TOPICS (meaning, there is allot to cover, no time for "what ifs").
In this book, DTL NAND (diode transistor logic Not And) requires three diodes, four resistors, two npn transistors. My book has a long explanation of component interaction I'd type it in but your book supposedly has a similar explination: it's long, 3 paragraphs, and includes things like calling Q2 a phase-splitter. It does not include a discussion of what D1 D2 D3 does except to say they do not allow reverse bias. It, however, takes 3 paragraphs of explaining it: and if you've done that I have to wonder why you do not know what they are for.
You said you'd verified the logic chart: I'm quite certain the logic cannot be verified by simple logic if diodes are not known to prevent reverse bias while making the output diagram.
This is why electrical characteristics are specified in the datasheets.
What happens when you shortcut them?
Did anyone mention this yet...
by Duane Benson
by Jeff Child
by Jake Hertz
