74HC139 (2-to-4 line decoder/demultiplexer) but for analog?

[michcfr]

Hello,
I would like to use the 74HC139 dual 2-to-4 line decoder/demultiplexer but for use in analog similar to the 75HC4051.
Do you know such a circuit?

Regards,
Michel

 

[KlausST]

Hi,

there are many.
Just go to the distributor if your choice an do a search for "analog mux" ... or similar...

Klaus

 

[BradtheRad]

The 4051 takes 3 bits (decimal 0-7), and activates 1 of 8 outputs.

Do you wish to split operation across two decoders?

I guess your truth table means that input value of 0 to 3 turns on decoder #1 only? That's the easy part.

And Input value 4 to 7 turns on decoder #2? So it functions as though it receives input value 0 to 3? That requires extra circuitry.

 

[michcfr]

yes I need to split operation across two decoders: two independant decoders taking each 2 bits and activate 1 of 4 outputs
Any idea/example of the extra circuitry?

thx

 

[wwfeldman]

if i understood the question, try MC14052BDG from ON Semiconductor

MC14052BDG onsemi | Integrated Circuits (ICs) | DigiKey Marketplace

Order today, ships today. MC14052BDG – 2 Circuit IC Switch 2:4 280Ohm 16-SOIC from onsemi. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

 

[michcfr]

if i understood the question, try MC14052BDG from ON Semiconductor

MC14052BDG onsemi | Integrated Circuits (ICs) | DigiKey Marketplace

Order today, ships today. MC14052BDG – 2 Circuit IC Switch 2:4 280Ohm 16-SOIC from onsemi. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

Thank you but it does not work. I need independant dual channels that is not the case of the xxxx4052
What I need is like two independant 74HC4051 (but of 4 channel instead of 8)

 

[schmitt trigger]

Something like the ADG1604 ?

 

[danadakk]

This what you want one diff chan in routed to 1 of 4 diff chan out ?

This is a processor part, lots of other resources left for use internal, see window on right.
But just this requires no code. Single chip.

Regards, Dana.

 

[BradtheRad]

yes I need to split operation across two decoders: two independant decoders taking each 2 bits and activate 1 of 4 outputs
Any idea/example of the extra circuitry?

thx

Bit 3 makes the difference. It changes to 1 when the input is 4-7.

Therefore I think you can use bit 3 to Enable one decoder and Disable the other. Run it through an invert-gate for one of them, before feeding it to its Enable pin.

Apply the other bits to both decoders as normal. This should cause lines 5 6 7 8 to operate correctly.

Of course the above method assumes that a disabled decoder turns off all outputs.

 

[michcfr]

Bit 3 makes the difference. It changes to 1 when the input is 4-7.

Therefore I think you can use bit 3 to Enable one decoder and Disable the other. Run it through an invert-gate for one of them, before feeding it to its Enable pin.

Apply the other bits to both decoders as normal. This should cause lines 5 6 7 8 to operate correctly.

Of course the above method assumes that a disabled decoder turns off all outputs.

Thank you BradtheRad
But your solution uses two 4051, right?
I need a single circuit to do the job to save space on my PCB

 

[michcfr]

Something like the ADG1604 ?

yes, but two circuits like this one in a single package (to save space on my PCB)

 

[michcfr]

This what you want one diff chan in routed to 1 of 4 diff chan out ?

This is a processor part, lots of other resources left for use internal, see window on right.
But just this requires no code. Single chip.

View attachment 162254


Regards, Dana.

thank you Dana
I just want two independant analog decoder in a single package

 

[danadakk]

That is a single chip solution. The schematic I showed shows a lot of symbols
wired together, but thats all on one chip. The right hand window shows only a
small amount of the chips resources were used, in case you need also stuff like
A/D, Vref, OpAmps, Comparators, DAC, Digital (Timers, Counters, LUT, Gates, Shift Register,....

The component catalog window, second from right, is a catalog of all components
for the chip chosen. In PSOC language a component is an onchip resource, in this
case there is a lot of components in this chip.

Note it also has an ARM core in it. but you dont have to use that. You can do designs
that require you write no code to those that do.

The chip used in the example I did is PSOC 5LP. The tool, PSOC Creator, is free, board
for dev work is $ 10.


Regards, Dana.

 

[danadakk]

What is the analog signal range voltages you want into the demux ?

What does the rest of the design do ?


Regards, Dana.

 

[stenzer]

Hi,

how does your input signal looks like i.e. amplitude, DC biasing, frequency, sinked/sourced current?

greets

 

[michcfr]

Hi,

how does your input signal looks like i.e. amplitude, DC biasing, frequency, sinked/sourced current?

greets

Hello,
Thank you for your interest
I want to use the decoder for general purpose analg and digital I/O: read ADC from MQ-135 like sensors, activate relay, LEDs....

 

[stenzer]

Ok, so it seems a single supply multiplexer with a "low" bandwidth should be fine. For LED applications keep the continous switched current in mind. Use the manufacturers product filter function to make a choice e.g. [1] for 2 x (4:1) .

[1] https://www.analog.com/en/parametri...|4683|546|4264|4270|2606|4458|4814|4811|s3|s5

 

[danadakk]

Hello,
Thank you for your interest
I want to use the decoder for general purpose analg and digital I/O: read ADC from MQ-135 like sensors, activate relay, LEDs....

The PSOC also has the A/D, the reference, ARM processor, demux both analog and digital.....

All the stuff on this part see attached catalog of part resources.


Regards, Dana.

 

[michcfr]

The PSOC also has the A/D, the reference, ARM processor, demux both analog and digital.....

All the stuff on this part see attached catalog of part resources.


Regards, Dana.

thank you for your response
I already have a microcontroler, what I need is a simple decoder circuit. thx

 

[michcfr]

Ok, so it seems a single supply multiplexer with a "low" bandwidth should be fine. For LED applications keep the continous switched current in mind. Use the manufacturers product filter function to make a choice e.g. [1] for 2 x (4:1) .

[1] https://www.analog.com/en/parametricsearch/12830#/p4683=(4:1) x 2&d=4263|4683|546|4264|4270|2606|4458|4814|4811|s3|s5

Thank you
Do not work: all the 14 models of type 2 x (4:1) have two digital select inputs (S0 and S1) that are COMMON to both switches. I need the switch to be independant.