Questions tagged [multiplexer]

A multiplexer selects one of two (or more) inputs based on a control input. It then outputs the selected input.

1
vote
2answers
669 views

7 segment LED display multiplexing for 9 digits

I want to build a 9-digit 7 segment LED display with basic components. I am planning to use a 4-inch 7 segment LED display and an Arduino board for my application. According to my understanding, I ...
1
vote
1answer
88 views

ADCs for sensor arrays

Most of the ADCs I see are designed for a single sensor voltage. I have read that this is not a problem for something like an acoustic sensor like a hydrophone because the ADC can be multiplexed so ...
0
votes
1answer
734 views

Decoders and multiplexer connected [closed]

This is from an assignment. I don't understand how they came to the answer shown, can you please explain?
0
votes
2answers
296 views

What does this digital multiplexer (CD54HCT151) output when the selected input is floating?

I'm not sure if I missed something, or it's omitted from the datasheet, but in any case, I couldn't tell what happens on the output when the selected input is floating. This post seems to imply there ...
0
votes
2answers
256 views

Alternative-switching multiple busses

In practice, the effects/results described below are much easier to achieve with an MC -- I know. However, for the sake of understanding and learning, I was considering the following scenario to be ...
0
votes
1answer
241 views

How to configure GPIO pins as digital outputs on LTC6804?

Can someone explain how to configure GPIOs as digital output pins on LTC6804. I have a MUX whose inputs are connected on GPIO2 - GPIO4 and the output is connected to GPIO1. My task is to control MUX ...
0
votes
1answer
56 views

Integrated Circuits for Signal Switching

Sometimes I need to switch digital signals between microcontrollers or devices. For example I have a serial device and I want to control to which microcontroller it is connected per digital pin. So ...
0
votes
3answers
757 views

Reducing the number of pins needed to read a 12-key keypad where the buttons are grounded?

Unfortunately, I'm not sure what the right question is; I'have a 12-key keypad. I wanted to utilise a matrix based approach, except that they all seem to be connected in such a way, that they're ...
0
votes
3answers
575 views

Is 74LS139 a DeMUX? If yes then how can I give it input and select lines?

I am trying to learn DEMUX. So, I have a 4 Channel DeMUX Diagram: From this diagram we can clearly see that a DEMUX needs 2 Select Lines and 1 Input to give 4 output lines. After that I have taken ...
0
votes
1answer
529 views

Constructing a 4-way multiplexer composed of 2-way multiplexers

I've constructed a schematic of a 2-way multiplexer, and also have made a 4-way one (and have a good idea of how to make 8, 16, etc. ones). However, my 4-way isn't a composition of 2-way multiplexers,...
0
votes
3answers
176 views

select any 2 of multiple inputs

I am trying to input any two of six sensor outputs to a microcontroller that has only two compatible ports. My first idea was to use two 74hc4051 8:1 MUX IC's but it would require 3+3=6 selection ...
1
vote
1answer
192 views

Using analog switches with ultrasonic sensors, what to look for?

I am designing an anemometer for university project. I intend to use analog switches to switch between ultrasonic sensors. I use this circuit as my first stage - it adds offset to the signal and has ...
0
votes
1answer
289 views

4 To 1 MUX - Figuring out the inputs

If i have a 2to1 mux together with logic gates like this: I can simply create a karnaugh map and test the different values of XYZ and get a function. From this i get the function f = x'z + yz + x'y ...
5
votes
1answer
592 views

Over voltage and reverse voltage protection of multiplexed ADC with voltage follower

I am designing a protection circuit for the ADC section of a design I am working on. There will be 8 analog signals being read by a single pin of the MCU via an 8 channel multiplexer. The analog ...
0
votes
1answer
240 views

How to calculate the segment array resistors in a multiplexed display array?

The situation: Four seven segment displays are multiplexed by a 16F648A. Now I need to calculate the required value for the segment resistors. Supply voltage 5V. Datasheet: Segment voltage 1,8V. ...
1
vote
1answer
73 views

Inside a multiplexer, can it work if i use a Pmos instaed of Nmos to reduce number of inverter?

To works well, inside a multiplexer we need the input signals inverted, but can we use a pmos instaed of a nmos with a inverted signal to delete the inverter? Is there any thouble? PSpice give me some ...
1
vote
3answers
562 views

74HC4051 Alternative - 4 Channel 1 circuit?

I have been playing with this multiplexor recently: 74HC4051. I have been searching all day for an alternative version where it is 4 channels instead. My task is simple and perhaps I am using the ...
0
votes
1answer
97 views

Should I use a Dual 4-channel analog multiplexer/demultiplexer for powering up 4 sensors and getting their readings?

74LV4052 Dual 4-channel analog multiplexer/demultiplexer I currently am using a multiplexor to connected to one analog channel from my Arduino. The multiplexor is connected to 4 pressure sensors that ...
7
votes
2answers
734 views

What is the purpose of diodes in flip-dot displays?

In most flip-dot displays i've seen, the electromagnets have a set of two diodes connected to them. This is also mentioned by David, who asked a question about the displays before. However, in the ...
-1
votes
2answers
551 views

Is it possible to use only ONE 4-to-1 Mux to allow 8 inputs?

So I am doing some CSE homework where we are told to implement a 3 bit equation using 8-to-1 mux and 4-to-1 muxs only which I understand. What I am wondering however is instead of cascading the muxs ...
-1
votes
1answer
154 views

How does shift register works as I/O multiplexer

I was checking on eBay for a CNC controller. I came across this unit, which provides 64 buttons. The micro is a 28pin PIC chip but there are 8x LS165A IC's on it. I am guessing there is some sort of ...
0
votes
2answers
9k views

4 to 1 multi-bit multiplexer implementation [Q]

We are tasked with creating a 4 to 1 multiplexer with 4-bit inputs. I believe I fully understand how to create a 4 to 1 1-bit multiplexer, but I completely do not understand what the 'input' side and '...
0
votes
1answer
54 views

multiplexing several channels

I'm designing a 6-channel amplifier which requires one LPF, one HPF, and one gain stage for each channel. I use 4*1 multiplexers for LPF and HPF, and 8*1 multiplexer for gain to control these ...
-1
votes
2answers
702 views

Simplify Boolean Equation to MUX

I have this Boolean equation which my professor told me it is possible to simplify to a MUX 4X1 but I can't do it. Would love some help! \$f(A, B, C, D) = A'B'C'D' + AB'CD' + A'BC'D' + ABCD\$
0
votes
3answers
429 views

ATMega input buffer

What happens if a AVR ATMega controller is doing something else when a input arrives on one of the serial ports? Does it has some sort of input buffering? I was thinking of using ATMega328 or simalar ...
-1
votes
1answer
610 views

How would one construct a NxN crossbar switch from solid state components? [duplicate]

I was trying to construct a 10x10 cross bar switch using relays -- something like: Question: is it possible to construct this by using solid state components (power transistors?) -- and if it is how ...
2
votes
2answers
526 views

What is this multiplexer doing in this design?

The design is from a Xilinx FPGA doc. I think these are preprogrammed look up tables because there is no select bit input, but on the bottom it says they are: Multiplexer[s] Controlled by ...
0
votes
1answer
2k views

10x10 RGB LED Matrix Multiplexing with Shiftregisters Bit Angle Modulation

I've build a 10x10 RGB LED Matrix. The LED's are connectet in rows and colums. Thats 40 pins (30 for RGB, 10 for GND). I got myself 5 74CH595 IC's and solderd everything together. I also added a 1A ...
0
votes
1answer
101 views

What is the exact order of execution to access SRAM using a multplexers?

Hello Electrical Engineering community, I am new to this community and indeed new to electronics So please be gentle, Thank You, In Advance... I have 2 x Alliance Memory ASC4008 SRAM IC Chips, I ...
8
votes
3answers
35k views

How do you implement the following function using nothing but 2:1 MUX?

I am having difficulties understanding how to implement boolean functions, particularly given that I may only use 2:1 muxes and the variable D as a residual variable. The function is as follows: $$ ...
2
votes
1answer
160 views

MUX output amplitude level

I am using MUX 4051(8:1 Mux and 3 select lines) IC in my application. My question is regarding magnitude of Output selected by select lines. Is Output voltage magnitude which is selected by select ...
3
votes
2answers
815 views

voltage drop across analog multiplexer

I am using a CD4051 analog multiplexer to interface with ADC. The system multiplexes from 8 identically setup inputs. The voltage at an Ch X pin of multiplexer appears exactly as it is on COM pin ...
0
votes
1answer
200 views

Analog Multiplexer as the first stage of DAQ system?

Recently I am designing a Data Acquisition system which utilizes FPGAs and ADCs. As my project needs to have a good balance between price, performance and quality, I have looked into the market to ...
1
vote
1answer
447 views

Alternative to diode to allow uniform and predictable voltage drops or On resistance

I'm trying to design a relatively high accuracy auto ranging Ohmmeter. A typical Arduino example can be found here: http://www.circuitstoday.com/ohmmeter-using-arduino The problem with this design ...
0
votes
1answer
81 views

Can the same address lines be used for multiple multiplexers?

I am connecting three demuxs and one mux to an arduino to be able to communicate with multiple ADCs. As there are many signals that need to go from the arduino to these 6 ADCs, I was thinking of using ...
0
votes
2answers
52k views

Block diagram of 16:1 MUX using four 4:1 MUX only

As far as I know we can make a 16:1 MUX using five 4:1 MUX. For four 4:1 MUX, I think we have to apply NOT to different selection lines but I am not getting the correct configuration to do that.
0
votes
2answers
225 views

Preparing Input and Selection voltages to a Multiplexer

I am trying to make a fast switching circuit that is able to switch a current (0-20mA) supplied by a current source (open-circuit voltage 100V) between two channels (i.e. switching between two pairs ...
0
votes
1answer
153 views

CD4067BE Multiplexer input always observed at all outputs

i am trying to use CD4067BE to switch an input between to output pins. I used 15V/0V Vdd/Vss for the mux, and connected all selection inputs and inhibit to 0V (Vss). I get the input signal at all ...
2
votes
1answer
334 views

Analog signal multiplexing with digital control

I need to route one of several analog signals to a single ADC input, using digital control signals. I have done this in the past using the 4051 multiplexer IC (or the more modern 74HC4051), but this ...
1
vote
1answer
411 views

Why isn't this decoder being inferred as a LUT?

I'm trying to model a stack which has push and pop operations. ...
2
votes
3answers
2k views

Displaying ASCII codes to an 7x5 LED Matrix

I want to know the best way to display ASCII binary code to a 7x5 LED matrix (cathode). The way I'm thinking to approach right now involves an decoder for each column (containing 7 bits, regarding the ...
0
votes
1answer
236 views

8 way demultiplexer hdl not working

I am trying to make a 8 way demultiplexer in hdl. The hdl is nog vhdl or verilog. It is interpreted specially for a nand2tetris cursus. I try to get something like this ...
1
vote
3answers
224 views

Compiling a simple 2-input multiplexer with GHDL fails

I started reading "The Designer's Guide to VHDL" by P. J. Ashenden, but I'm already stuck after exercise 9, here is my code: ...
-3
votes
1answer
7k views

8:1 mux from minimum 2:1 and 4:1 mux

If 2:1 and 4:1 Mux are available in any industry. And If cost of 2:1 is 3Rs. and 4:1 is 5Rs. per unit. Then how much minimum units and cost are required to construct a 8:1 Mux? 1) one 2:1 Mux 2) one 2:...
1
vote
1answer
208 views

Am I using this multiplexer (SN74LS153N) correctly?

I'm trying to make an ATtiny85 control an SN74LS153N dual 4-to-1 multiplexer in order to read state of several switches using a single pin (three pins actually), but am having trouble understanding ...
0
votes
1answer
334 views

3x3 LED grid using NPN transistors to switch (Arduino)

I am trying to design a basic project to multiplex a 3x3 LED grid in a common anode arrangement. In order to avoid sinking (sourcing?) too much current from the digital I/O pins of the Arduino I would ...
0
votes
2answers
274 views

Analog crosspoint switches [closed]

I am looking for analog crosspoint ICs that have a high number of channels, that can operate over 10V and are bi-directional. Currently I am using the circuit CD22M3494 and I am looking for an ...
0
votes
1answer
339 views

Function of demultiplexers in Register File

What is the function of demultiplexers (DMX) in this Logisim diagram of a Register File design: Also could you explain the meaning of: dreg,sreg,treg dsel,ssel,tsel dwrite,swrite,twrite
0
votes
1answer
84 views

AD8113 operating voltage

I'm looking at high channel multiplexers that can operate at voltages over 10V and for this component it says that the supply voltage is 12V which is okay for my application, but when you read under ...
0
votes
1answer
12k views

Implement Boolean function using only 4x1 multiplexer considering A and D as input and B,C as selection values

F(A,B,C,D) = Σm(0,1,3,4,6,7,11,12,14,15) How do I use A and D as input and use only 2 selection lines for a 4 variable function?