Multiplexer help

Thread Starter

Aklem

Joined Jun 18, 2009
41
im using a multiplexer/demultiplexer
(i think)

i need to know how to use it...

it is very complex

on the ic it says: "R&E" which is in a diamond (logo)
also on the ic: "SCL 4053 BE"
next line: "9310 840745"


i bought it at sayal electronics
the description on the bag is: "CMOS ANALOG MULTIPLEXER DEMUX"
part number is "4053-2"

it has 16 pins (look at the datasheet)



THE DATA SHEET THAT I FOUND FOR THIS CHIP (i dont know if this is the right one)
http://www.alldatasheet.com/view.jsp?Searchword=4053
 
Last edited by a moderator:

lightingman

Joined Apr 19, 2007
374
Hi,

What you have in mind is probably "time division multiplexing" It can (as I have) be used for sending digital or analog signals down just a couple of wires. I used this type of multiplexing to send 256 analog lighting channels down a balanced mic cable (not to be confused with DMX). one of the cores was used as a clock/sync signal, as follows:- The voltage was biased at 6 volts and the clock was sent at 16KHz with the level of +6 to +12 volts. At every 256th pulse, one pulse (the sync) was sent at the level of 6 volts to 0 volts.
At the other end, two comparators were used to separate the signal into the two signals of 0 volt to +5 volts. The clock clocked the counters and the sync reset the counters after 256 clocks. On each clock the analog signal on the other wire was clocked into 256 sample and hold circuits. And that is a good example of the advantage of multiplexing.

The other is to multiplex data to 7 seg displays (see attached file). This reduces the number of wires to a front panel, as all the separate segments can be connected together. It also makes interfacing to micros easier.

Daniel.
 

Attachments

Thread Starter

Aklem

Joined Jun 18, 2009
41
nope...


well what im tying to do is multiplex multiple sensors together (as many as i can)

AND BECAUSE I BOUGHT 4


(since it says its a mux/demux i/0)
i want to multiplex multiple leds
 

lightingman

Joined Apr 19, 2007
374
OK...

Yes, you can multiplex as many sensors as you wish. If you use a CD4051, you can multiplex up to 8 sensors into one input such as an A to D converter.
If you use a CD4067, you can multiplex 16 sensors. You can, using the 4051 expand to as many as you like (in multiples of 8). Or with the 4067 in multiples of 16. If you need to expand using multiple 4051's or 4067's, you just select each chip using a decoder (4028 + inverters or 4515) on the upper 4 bits of the address.

You need to address the 4051 in binary (000 = input 0, 001 = 1, 010 = 2 and so on to 111 = 7). each time the address is valid, read the output of the 4051 (pin 3).

That is it.

You can do the same for your LED's.... Do you want a sample schematic?

Daniel.
 

Thread Starter

Aklem

Joined Jun 18, 2009
41
I want a full truth chart... I know how to address the controls in binary but i dont understand why there are 3 in outs and 6 other seperate in outs? I thought it would only be lets say... 16 to one i need a comprehensive truth chart... (not one in datasheet) maby a few examples how to address certain imputs to outputs
 

Thread Starter

Aklem

Joined Jun 18, 2009
41
well where can i go for the chips? radio shack isint here anymore (for me)
sayal sucks and has no datasheets (sayal.com)
my mom hates ordering
so where can i go?
sayal only has one analog multyplexer, the one i have now
 

lightingman

Joined Apr 19, 2007
374
Hi again,

You can switch analog signals through these switches. But the analog, or digital input/output voltage should not go higher than VDD or lower than VEE.

Crumbs man, where are you?

Send me a private message with your address, and I will send you some chips...

Daniel.
 

Thread Starter

Aklem

Joined Jun 18, 2009
41
so if it dosent say analog or is a 4051 then does it have analog signal?
sorry for asking...

[also btw im only 13 so if you know, parents are restriciting]
yep 13... i know visual basic, c++, wiring (arduino), processing, glovepie, and other ones i forgot... :(
my mom wont let me on the comp for long and now im at my cottage..
(dialup 12h per month)

she dosent like ordering, or travaling more than 2h (yep 2h for a trip to sayal)

im in canada
 

lightingman

Joined Apr 19, 2007
374
Well 13 !!!

It is great to see young people showing an interest in electronics. This forum is a great place to learn from other people's projects and experience.

Look at the 4051 as a 1 pole, 8 way switch. Instead of selecting each contact by turning the shaft, you select each channel (contact) by addressing it in binary.
Where as a mechanical switch has a maximum voltage and current rating, so does the 4051.

When the switch is on, it is basically a resistor of around 50 to 150 Ohms. So it is a device for switching low currents, and signals up to around 10MHz.

The basic rule is that any input must not go more than 0.5 volts above the device supply voltage, or less than -0.5 volts bellow ground, or in the case of the 4051, 2 and 3, VEE.

So if the supply on the VDD pin is +5 volts, the VSS pin is at 0 volts and the VEE pin is at -5 volts. Then the switch inputs can swing between +5.5 volts and -5.5 volts (analog).

If the input voltage goes beyond these levels, clipping of the waveform will occur and if too much current flows under these conditions, damage to the device will occur.

Hope this helps.

Daniel.
 
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Thread Starter

Aklem

Joined Jun 18, 2009
41
it helps thx...
((((((so if i buy the 4051 and read sensor inputs (ir phototransistor + ir led)
it will return a analog voltage between Vcc and Vdd?
sorry for asking so many times...))))))
EDIT: okay iknow now

also if you want to see my projects...
(if you have the intrest)
my youtube account is http://www.youtube.com/aktechfreak

and my website is http://www.aklem.com

I have some code up there as well as my embedded youtube videos
(i have made a 3x3x3 led cube, and a nuchuck reader that uses a lcd)
 
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Thread Starter

Aklem

Joined Jun 18, 2009
41
im done... il let this thread die....
i will buy the multiplixer even its a long drive
probably use it for multiplexing multiple sensors for microcontrolers
 
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