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I want to know how can i tell from a Demultiplexer's datasheet that it maintains the output logic level after the address inputs have been changed.

EDIT: I do not have any datasheet to post since I have not found any demultiplexer with the 'latching' feature that I want. What I am asking here is how to understand that a Demux has this latching feature from looking at a datasheet

Example: Say i want to turn on 3 leds:

schematic

simulate this circuit – Schematic created using CircuitLab

But after the LED1 is turned ON, and I focus (point on) the second led, I want the first led to stay ON.

I tried searching on the datasheets for the keyword "Latching" or "latch" but it found nothing. Maybe i just searched on the wrong datasheets (like this one) , or is there another keyword?

In this website also says: Also some have latches built into their outputs to maintain the output logic level after the address inputs have been changed So I know some of them have this feature.

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  • \$\begingroup\$ please add a link to the datasheet ... add to the post, NOT in comments \$\endgroup\$
    – jsotola
    Mar 1, 2021 at 21:44
  • \$\begingroup\$ I cannot find a Demultiplexer with a 'latching' feature, so i do not have any datasheet to post. (I ended up adding one datasheet tho) \$\endgroup\$ Mar 1, 2021 at 21:46
  • \$\begingroup\$ ok then ... yes, the multiplexer's datasheet should show whether the output is latched \$\endgroup\$
    – jsotola
    Mar 1, 2021 at 21:50
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    \$\begingroup\$ in the link you provided, table 3 shows that it does not latch outputs \$\endgroup\$
    – jsotola
    Mar 1, 2021 at 21:54
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    \$\begingroup\$ search for addressable latch \$\endgroup\$
    – jsotola
    Mar 1, 2021 at 22:28

1 Answer 1

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By definition, demultiplexers follow their select inputs and don't remember previous states. They don't have storage. There's nothing to 'tell' from the datasheet. It's like asking if a NAND gate can hold its output (it can't), so there would be no statement about that.

If you want that functionality of driving more than one LED at a time, consider that you have 3 MCU pins driving 3 LEDs - why not just use the MCU pins directly?

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