All Questions
12
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What is the quiescent power dissipated by a TTL totem-pole output stage?
In High-Speed Digital Design by Johnson and Graham, the quiescent power of a TTL totem-pole is given as:
$$P_{quies} = \frac{0.4I_{sink} + 1.0I_{source}}{2}$$
I am fairly certain the 1.0 is a mistake ...
- 209
5
votes
2
answers
612
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TTL NAND gate analysis
I was looking into Millman's Microelectronics book, 2nd edition, pp. 245 - TTL NAND Gate.
I am a beginner in electronics and was looking into this book just because of an assignment problem about a ...
- 153
1
vote
2
answers
431
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BJT circuit with totem pole output
In the circuit above, I don't understand how to close and open the BJT that I circled.
To be specific, I think that when I give input 1 the circled BJT should be opened, but how? What is the voltage ...
- 11
2
votes
1
answer
666
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BJT transistor max switching frequency vs FET in high frequency computer architecture
Why arent BJTs used with RISC architectures to produce very high speed relatively sparse CPUs? My understanding is that BJTs don't have the forward bias gate capacitance requirements of FETs which is ...
- 43
1
vote
4
answers
250
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Collector current in a BJT transistor whose base and emitter are forward biased
I'm reading a book about electronics and I have a doubt about a NAND gate implemented with Transistor-Transistor Logic. The question I have is actually about BJT transistors specifically (not the gate ...
- 1,259
1
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1
answer
2k
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Input and Output Impedance of a TTL NAND Gate
Basically I wanna know how to calculate the input and output impedance of this basic TTL NAND gate I have looked at several books and websites but found nothing useful , can anyone help me please.
...
3
votes
2
answers
3k
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Working of a transistor in a TTL inverter circuit
I was referring to TTL inverter circuit in the book Digital fundamentals by Thomas Floyd and its working principles first proposition went as follows:
When input is HIGH, Base emitter of Q1 is ...
- 55
0
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2
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4k
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What is the point of 2 inverters in series? [duplicate]
In the datasheet for the Nexperia HEF4543B, in the logic diagram, there are 2 inverters in series:
What is the point of these inverters in series?
- 652
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1
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108
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TTL gate characteristics
In case of BJT for example, the input characteristics can be described with \$I_B=f(V_{BE})\$ and output characteristics with \$I_C=f(V_{CE})\$.
How can the input and output characteristics be ...
- 280
1
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1
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Which area of physics deals with principle of work of BJTs, diodes and other semiconductor elements and which book do you suggest covering this? [closed]
Which area of physics deals with principle of work of BJTs, diodes,...?
I'm familiar with equations that describe operation of these elements but I have no idea how they work "internally". I started ...
0
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1
answer
479
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TTL gate function
Can you explain the logic function of this TTL gate? I think it is
$$
Y = \overline{AB+CD} \
$$
but I am not sure.
If
$$
V_1=5V \\
V_2=0V
$$
does the transistor Q1 work in reverse-active mode?
3
votes
4
answers
2k
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Purpose of pullup resistor in BJT LED driver circuit
One answer to this question suggests the following circuit to drive a LED from an open collector output of a 74LS47:
simulate this circuit – Schematic created using CircuitLab
What is the ...
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