Digital electronics use a finite number of states, unlike analog electronics that treat continuous signals. Digital logic is used to perform arithmetic operations with electric signals, and constitutes the base for building CPUs.
-2
votes
0answers
17 views
Counter design with 74193
Count down 5 4 3 2 1 0 after this,
Count down 4 3 2 1 0 after this,
Count down 3 2 1 0 after this,
Count down 2 1 0 after this,
Count down 1 0 after this,
How can i design this problem by ...
1
vote
1answer
45 views
How to read a hex inverter gate datasheet? 74LS04
I'm new to digital electronics and I want to simulate in ltspice a circuit which contains a couple of 74LS04 inverters. What represents the "Test conditions" under the switching characteristics in the ...
0
votes
0answers
13 views
Clock frequency from hold, setup and propagation time of flipflop
What should be the maximum frequency of clock as a relation of hold time, setup time and propagation time?
0
votes
2answers
93 views
What is function of this complicated circuit?
Here is my task:
a) Explain principle of working of circuit below. Draw waveforms of voltage
at points A, B, C, D and Q, as well as capacitors voltage waveforms.
b) What is minimum time constant of ...
0
votes
1answer
20 views
xor Boolean algebra simplification
I am doing boolean algebra simplification and got the result of (A.B) xor(C xor D) Does (A.B) xor (C xor D) = (A.B) xor C xor D ?
0
votes
0answers
14 views
How do you draw a truth table on stack electronic? [migrated]
I am new to this site and trying to figure out how to draw a truth table on the site. Can someone help please ?
0
votes
0answers
42 views
How to solve logic gate with RC circuits?
I'm new to digital electronics and I've started to solve some circuits involving nor gates and RC circuits. I've understood how to solve a couple of them but I am stuck in this problem: ...
5
votes
1answer
71 views
CMOS transistors for educational purposes
I am currently teaching my daughters Digital Electronics, ages 9 and 12. In doing so, I wanted to introduce them to CMOS logic, since I feel that a hands-on approach is always better than just doing ...
-5
votes
0answers
18 views
Difference between encoding and decoding in DLD [on hold]
I am search on google but not found any relevant material. I need some 3 to 4 differences, some diagram and some examples about encoding and decoding in digital logic design.
-4
votes
1answer
106 views
What is function of this circuit?
Here is my task (digital electronics)
For circuit below find:
a) In which logic it operates and what is function of this circuit;
b) Max. number of outputs, if circuit is part of chain of same ...
1
vote
3answers
71 views
How does the NAND Gate work using Transistors
I recently learned about the NAND gate circuit with transistors in my circuits class as shown below.
Unfortunately I'm having a very difficult time comprehending as to why the output is 1 when A or ...
-6
votes
0answers
34 views
Kitchen Timer . [closed]
I have to draw schematics on a kitchen Timer that counts down from a selected time (MM:SS) to 00:00(starts an alarm) . Counts up if the initial state is 00:00 , to 99:59 (without triggering the alarm) ...
0
votes
0answers
41 views
Moving from analogue design to digital design [closed]
I am a graduate thinking of accepting a mixed signal analogue or digital job. My problem is, I am not sure what I want to be doing for a long time. I like analogue, digital and computers. If it ...
0
votes
0answers
29 views
Constructing 16-1 Multiplexer from four 4-1 Multiplexers and a 2-4 Decoder
I have to show how to construct 16-1 Multiplexer from four 4-1 Multiplexers and a 2-4 Decoder.
I tried creating 8-1 MUX from two 4-1 MUXes (using enable pin), but have no clue how to stack more MUXes ...
0
votes
1answer
32 views
Another question about CMOS tri-state buffer internal structure
About my previous question: CMOS tri-state buffer internal structure
I have just one more question:
is the value that "activates" the transistor related to the value of the Output? Because if I ...
0
votes
2answers
48 views
CMOS tri-state buffer internal structure
I was trying to understand the CMOS tri-state buffer internal structure with logic gates...
The image is similar to this one:
Anyway, I'm not understanding the logic I think something is escaping:
...
0
votes
0answers
27 views
Calculation in sigma delta ADC?
I'm using a 24 bit sigma delta adc with internal reference 0.8 volts,SNDR 80 dB.
max input swing +-500mV.
so I have a following doubts.
1]does this have resolution of 0.8/2^24=4.76*10^-8
so this ...
0
votes
3answers
100 views
Soldering arduino I/O pins
I'm planning to make a permanent arduino project that I'm not planning to take apart. Can I solder the jumper cables and the arduino digital pins together? Will that harm the project or arduino in any ...
0
votes
1answer
22 views
How do I design a cascade network of 1-bit comparators to determine if two n-bit numbers are equal?
I'm reading through the "Logic Design" chapter in Givone's Digitial Principles and Design and this is one of the problems at the end of the chapter. I read the section on comparators thoroughly, but ...
1
vote
1answer
40 views
BAT54c and TVS SM6T39A application usage?
I need to design a circuit for my vehicle tracking application and i am using pic micro-controller . I need to capture the iginition status of a vehicle using the micro-controller ,where i have ...
1
vote
1answer
32 views
How do you represent a SOP in terms of NAND?
Is there a specific technique to convert SOPs to NAND.
I have the following expression:
A'BC + ABC'
And would like to represent it using only NAND gates.
A'BC=(((AB')')'C')'
ABC'=(((A'B')')'C')'
...
0
votes
1answer
43 views
gate equivalence table?
I am looking for an official reference for "gate equivalence". I have 2 conflicting values for gate equivalence for a flip-flop from 2 different books, and no GE for a mux. My question: Is there a ...
0
votes
1answer
49 views
555 timer digital clock
How would you go about connecting a 555 timer to a circuit with a 16x2 LCD display, which is already connected, to create a digital clock that counts the time? Do you have a sample of how this code ...
0
votes
1answer
37 views
How to evaluate equivalent 'samples per second' from Time base value?
The following is from Tek DSO manual about the Time base and sample rates.
When i turn the knob further, i am able to read values like M 100ms or M 250ms.
What woud these evaluate to in terms of ...
0
votes
1answer
49 views
Mosfet push pull gate driver: To high base voltage?
I'm trying to create a Mosfet push pull gate driver using discrete components.
I already made a simpler one to drive most mosfets from 3.3v using 2 npn transistors. One to increase the voltage ...
0
votes
1answer
46 views
How to connect stages in digital logic?
Let's say I have a logic stage doing an operation on 2 inputs, giving me an output.
How could I use this output to forward it into another set of logic stage, without having to put everything in the ...
0
votes
1answer
59 views
Logic Gates - Did I connect them correctly?
I have 2 logic gates problems I need to solve applying de morgan's laws and I just wanted to make sure whether I did it correctly or not.
I am supposed to create the function F=abc+d using only the ...
0
votes
1answer
32 views
Detection of CAN-BUS signal direction
I trying to detect if a "dominant" state on the bus
is set from a specific CAN-Node.
For this I place a "bridge" between the Node and the Bus.
I don't want to forward each frame with a MCU, rather I ...
2
votes
4answers
118 views
Digital Circuit to Check for Majority
I have 31 digital inputs (each is high or low) and want one digital output which is high only if at least 16 inputs are high. How can I implement this "majority" function (which is also the most ...
1
vote
1answer
56 views
Can the two “high” input to a digital logic gate have different voltage values?
Suppose there is a logic gate and it has two inputs.I want both the inputs to be "high" i.e logic 1, can i have two different voltage values at these two inputs? e.g 3v on one and 4v on another?
0
votes
2answers
30 views
Voltage supervisory circuit selection
I am trying to understand how to choose a suitable voltage supervisor IC for a given project. I have two questions:
if I have a digital IC, in its datasheet there is information about the minimum ...
3
votes
3answers
308 views
What is the maximum allowable load capacitance for 74HC04?
Does anybody know the maximum allowable load capacitance for 74HC04? In the datasheet, nothing is mentioned in the "Limiting values" section. Some of the dynamic characteristics are given for a load ...
2
votes
0answers
68 views
Two different ways of writing the same thing but generating different behaviours in Verilog
I have a part of Verilog code that is basically trying to synthesize a flip-flop. I have been experimenting and it seems that I can come up with two ways of writing it.
The first way being :
...
0
votes
2answers
67 views
7400 series CMOS vs 4000 series logic IC
I understand the traditional difference between the 7400 series and the 4000 series logic ICs, but since there are CMOS versions of the 7400 series, is there an advantage to use the 7400 CMOS version ...
-2
votes
3answers
126 views
People says machine understands binary code, that is 0 and 1 is that literally true?
What i meant to say that 0 and 1 is still a perceptive number that human to understand so how come machine understands this? If machine can get 0 and 1 it can equally understand alphabets also. So ...
0
votes
1answer
26 views
Logic Expression
What is the switching expression of corresponding to the equation:
$$F\left(A,B,C,D\right)=\Sigma\left(1,4,5,9,11,12\right)$$
After using the K map I am getting the answer as:
...
0
votes
1answer
62 views
Introductory Digital logic/design question
How can I abstractly describe a sequence of instructions/function at a register transfer level, given a certain set of instructions.
For example, here is the type of questions that we would be asked ...
-3
votes
0answers
16 views
I know the answer, but I do not see how to answer the specific question? [migrated]
Sorry, this question is about answers.
I would like to answer the question:
Make a momentary switch control a toggle
Please, help.
Thank you.
0
votes
1answer
40 views
NOR Gate is Working Correctly with Vcc Pin Disconnected
I modified my Sega Master System to have a pause button on the actual controller. To process the signal, I soldered a quad NOR gate to the I/O and CPU circuits in the console. The idea is that the ...
0
votes
2answers
177 views
Static Hazard in Specific Value or Any changes?
I have one solved problem, My teacher solved it as follows:
and says
with B=C=D=1 for change value of 'A' from one to zero we have Static-Hazard '1'.
but I think we should say
with ...
-2
votes
1answer
53 views
signed maximum detector vhdl [closed]
Sorry I've asked a similar question but I didn't get a answer so I posted this question
I'm currently designing a maximum detector in VHDL which is part of my homework.
The whole system consists of ...
0
votes
1answer
45 views
Digital circuit to sense both high side and low side switches
Currently, I have a digital circuit running parallel to a LED to measure if it is driven high, with a zener clipper circuit to clip the voltage to 3.3v (max safe for microcontroller).
Current circuit ...
-1
votes
1answer
58 views
NPN transistor high resistance across collector and emitter [closed]
I have a MMBT3904L SMT transistor (datasheet http://www.onsemi.com/pub_link/Collateral/MMBT3904LT1-D.PDF) and I am getting wierd behavior accross the emitter and collecter terminals. The base is held ...
0
votes
1answer
34 views
Changing the data logging rate on a Tektronix DSO
Currently, for a continuous waveform, i am able to log data from the Tektronix TBA 1064 DSO as .csv files. The time interval between two samples currently is around 4 * E-08 (by default).
My ...
0
votes
1answer
44 views
Input Rerouting using IC or Transistor Application
I'm quite new to Electronics and I have this assignment I have to do - I need to "reroute" the input according to his type.
I have these two inputs, which can be both analog (1 channel, same value on ...
0
votes
0answers
35 views
VHDL - difference between concurrent statements and sequential statements [duplicate]
I'm fairly new to programming an FPGA using VHDL and I have a doubt. I understand that concurrent statements (the ones written outside the process) are executed simultaneously and sequential ...
0
votes
1answer
57 views
Current amplifier for digital output
I want to be able to control an external laser diode w/ a digital controller.
The laser diode requires 3V and 130-280ma to turn on.
The digital controller I have is NI USB-6501 ...
0
votes
0answers
23 views
State Equations and Transition Table
I was wondering how you would derive a circuit's state and output equations from a given transition table.
Such as:
A(t+1) = _____
B(t+1) = _____
Z = _____ (output)
2
votes
3answers
99 views
Designing a factory reset switch
I want to add a factory reset onto a PCB design I am working on. Basically, I want it to be a switch (or combination of) that will never be "accidentally" closed and therefore accidentally factory ...
0
votes
2answers
43 views
Logic expression with k-map or minterms-maxterms
I have 4 inputs and 3 outputs.
Two of the outputs contain both 0s and 1s, so their expressions are easy to write.
However, one of the outputs has only 0s. How can I write its logic expression by ...
