Analog Multiplexers and Digital Multiplexers

Multiplexers are just an array of switches to control multiple signal sources to multiple outputs.

Whether they are digital or analogue makes no difference, they are just switches to either isolate or redirect signals along different paths.

John.

<Whether they are digital or analogue makes no difference,>

Dear John,

You really meant " You can multiplex all--Analogue mA/mV , on-off , or digital pulse trains-but the multiplexed data-string will be Digital-to enable storing, computing/ controlling with,retrieving. "

BR

MM

What I really meant I said MUKUL.....

Switches can be either off or on, its a basic definition of a switch isn't it?... the signals controlled by the switches can be anything.

John.

another explain,

digital multipexer si an array of switcher to switch digital signal and analog signal into differnet output, and isolate input and output simultanietly without amplification. of cause they have lost a lttle. like we often used sijmple cd4066. which can be either digital switcher or analog switcher etc.

there are existing in every pal, gal, fgal, microchip , tv switcher etc.

in another hand, in broadcast, communication analog signal, we can mix lots of lower frequency signal into a wider frequency band high frequency signalwe can call it as multiplexer or modulator as well. then divide it into manuy different low frequency signal. demodulator or demultiplex. this is used oten in communication.

similarly, encode multiplexer, fdma, cdma... oh, its a complex topic now.

Thanks--you painted a more complete picture.

Complex topic simplified.

I will say there are some differences between analogue and digital MUX. The analogue is bidirectional and can handle DC-level to a max frequency. The digital is only one way and can only handle digital levels.

Anders

"analogue is bidirectional ....The digital is only one way and can only handle digital levels." I'll have to disagree with these statements. Analog or Digital can mean a communication type signal or a status type signal (Analog = frequency, amplitude communications used in modems or current flow or voltage level representing a physical variable such as temperature, Digital= bytes and words in data packets or a status point represented by a voltage present or not). The former are typically bi-directional while the latter will be as you indicated uni-directional.

I think we are not talking about the same things but it has the same name.

For me an analogue MUX are chips like i.e. 74xC4051, -4052 -4351. They can select an analogue signals from different sources and transfer them to a common output. They use analogue switches as "gates". These MUX are bidirectional and can handle both positive and negative signal levels from zero to ±VDD.

The digital MUX are chips like i.e. 74xx151, -251 -4512. They can select digital levels, TTL or CMOS. They use digital gates as switches and can only transfer data from inputs to output.

Please, can you tell me your thinking?

Anders

This post is so clear that NOW novice data loggers can start hooking up circuitry- after learning data logging protocol.

Ah! You are absolutely correct. I think of them as standalone devices or finished products. These products utilize the chips you think of with the potentially added features of modem control, line drivers and gateways (protocol conversion. Of course, as soon as I saw your response I "remembered" there are two meanings to the same terms. Thanks for clearing the air on that.