# What is this kind of “Multiplexer” called?

First of all I am new to electronics so i might use wrong terms.

What is this electronic component called or is it even a thing (Can it be bought)?

I have 10 input wires/channels for example. Only one wire is active at a time (5v).

The "multiplexer" output is the number of the active wire/channel.

• perhaps a "priority encoder" – Peter Bennett Sep 11 '18 at 15:32
• You might want to describe how your thing is different than an ordinary multiplexer – PlasmaHH Sep 11 '18 at 15:33
• you ought to say logic inputs not just wires – Sunnyskyguy EE75 Sep 11 '18 at 15:34
• en.wikipedia.org/wiki/Priority_encoder Peter is correct. – Sunnyskyguy EE75 Sep 11 '18 at 15:35

A digital encoder or Priority Encoder. They will often have $2^n$ inputs and $n$ outputs.

Additionally there will be an any-active output and an enable input.

You can combine multiple encoders together using these extra pins

Do you want a selected digital output to follow a digital input signal? Then demultiplexer is what you want, such as 74HC154

https://assets.nexperia.com/documents/data-sheet/74HC_HCT154.pdf

If you want to selected digital input to be fed to an output, then a multiplexer is what you want, such as 74HC150, altho they are not around anymore.

If you want an analog input/out to connect to a selected input/output, then an analog switch is what you want, such as DG406

https://www.intersil.com/content/dam/Intersil/documents/dg40/dg406-407.pdf

If you wanted to read the state of 10 switches for example, a part like cd74hc4067 would be good. Connect the swithces to a pin and Gnd. Connect the common to something like an Arduino input with its internal pullup enabled. Then read the inputs one at a time - switches connected to Gnd would read low, switches that were open would read high. Thus 4 pins to select the switch, one input pin, to read 16 inputs.

Alternately two shift-in registers could do the same, and only use 3 pins, altho each input to the shift register would need its own pullup resistor. cd74HC165 for example