Electrical Engineering Stack Exchange
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Questions tagged [multiplexer]

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

Multiplexers switch between 2 or more input channels to one output channel. Each input channel can consist of one or more bits. For 2 input channels 1 select bit is needed, for 4 input channels 2 select bits, and for 8 input channels 3 select bits.

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Large Multiplexers/Data Selectors

I'm looking for a multiplexer IC with 128:1 or more inputs (256 would be quite nice). I would have thought such a device would be quite common yet I'm having a tough time locating it. It could be that I'm looking at the wrong places but somehow I…
Saad
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Use of tristates vs multiplexers in a RAM

Why are tristates favored over multiplexers to select the output from RAM? The explanation that I've heard of is that the RAM is too large for using a multiplexer but I need more details. A theory we've come up with is that using a multiplexer would…
Sid
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What is the difference between an analogue multiplexer and digital multiplexer?

As far as I know, analogue multiplexing is used to take voltage samples from many channels in a short time. It passes the voltages from an input to the ADC without amplifying them. I guess buffer them? But is that called analogue because of the…
GNZ
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Analog Multiplexer?

I am almost completely new to electronics. Recently I was reading about an 'analog multiplexer' I know what a multiplexer does, and how it works, but is there such a thing as a 'digital multiplexer' that would just give +5v when a channel was…
A.R.
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Differences between a FET multiplexer and regular digital multiplexer?

I need a MUX 8-1 with a very fast propagation delay; <10ns. I was searching Digikey and found a category of digital muxes called FET multiplexers, and their propagation delay is insanely fast < 0.25ns, which seems too good to be true. What are the…
Daniel
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What is Vee on a 74hc4051 mux?

The 74HC4051 Mux (spec is here: http://www.nxp.com/documents/data_sheet/74HC_HCT4051.pdf) has 8 input/output pins labelled Y, one output/input pin labelled Z, three digital selectors S0, S1, S2, and an active-low enable pin E (bar). That all seems…
Dov
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8:1 multiplexer to 6:1 multiplexer

I have 6 inputs that I want to insert in a 8-1 multiplexer. I just want to know how to modify the 8-1 mux to support only 6 inputs. I mean the last two rows on the truth table of the 8-1 won't be available. This is the 8-1 mux I am using: and its…
zaiz2s
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How a 2-1 multiplexer (MUX) work?

I haven't done EE for quite a long time. I need to implement some MUX, so I started with a two-way MUX. But I don't understand how to make the decision: Wiki- Multiplexer A truth table will show that This truth table shows that when S=0 then …
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How to build an 8 output demultiplexer, using only the two output demultiplexers?

I think its some basic question but I'm really confused about MUX/DEMUX. Should I use 2-output demux's outs for in?
pikk
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Peripheral interface design

I’d welcome some advice on a hobbyist peripheral interface design. This must use 74-series logic and have the lowest package count. There is a notional CPU which is not shown in the sketch below. It is separate from the peripheral interface and…
David00
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Best way to build a 64-bit output multiplexer

I'm looking to create something to multiplex N 64 bit signals together. The goal of the project is to provide digital switching between a library of old cartridge based video games. Essentially I want to have a number of cartridges always 'hooked…
Kallin Nagelberg
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Multiplex dip switch input to microcontroller

I have 3 DIP switch packages with 8 switches each, and not enough inputs on my microcontroller. This article (you have to download the pdf to see the schematic) gives an example of what I want to do. In the comments section, many people say the…
Marlon Smith
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How to drive a cd4051 analog mux with buttons as channel selector?

I 'd like to control an analog multiplexer cd4051 as a 8-1 switch with buttons that will act as channel selector (1-8) I know how to do it with Arduino but is there any other way to read the state of 8 buttons and provide a 3 bit word as separate…
John Am
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A circuit that outputs one input voltage by default, or another if it is present

I'm trying to come up with a simple design that will take two analog inputs voltages (~0.2-1.6 V each). One is an "internal" voltage and should always be present. The second "external" input can be present, or can be not connected, floating,…
DanoldKong
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Regarding OFDM (Orthogonal Frequency Division multiplexing)

Could you please briefly explain the IEEE 802.11a OFDM packet structure? In particular, What is meant by "symbol" here? What is the purpose of the packet preamble? What is a "short training symbol" and what is its purpose? What is a "long training…
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