74157: Difference between revisions

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== Signal descriptions ==
== Signal descriptions ==
If /E is high, then all 4 Y output pins output as low,  otherwise, if S is low, for each set of pins starting with the same number, Y is equal to I0,  otherwise, if S is high, then Y is equal to I1.
If /E is high, then all 4 Y output pins output as low,  otherwise, if S is low, for each set of pins starting with the same number, Y is equal to I0,  otherwise, if S is high, then Y is equal to I1.
Function table (L/H/X = low/high/irrelevant):
{| class="tabular" style="text-align:center;"
! <tt>/E</tt> || <tt>S</tt> || <tt>I0</tt> || <tt>I1</tt> || <tt>Y</tt>
|-
| H || X || X || X || L
|-
| L || L || L || X || L
|-
| L || L || H || X || H
|-
| L || H || X || L || L
|-
| L || H || X || H || H
|}
== References ==
* [https://www.ti.com/product/SN74LS157 TI - SN74LS157]
[[Category:7400 series|157]]
[[Category:7400 series|157]]

Revision as of 10:25, 16 April 2023

The 74157 (variants 74LS157, 74HC157) is a 74-series logic IC with four 2-input multiplexers sharing a single select line.

74157 Pinout

       .--\/--.
  S -> |01  16| -- +5V
1I0 -> |02  15| <- /E
1I1 -> |03  14| <- 4I0
 1Y <- |04  13| <- 4I1
2I0 -> |05  12| -> 4Y
2I1 -> |06  11| <- 3I0
 2Y <- |07  10| <- 3I1
Gnd -- |08  09| -> 3Y
       `------'

Signal descriptions

If /E is high, then all 4 Y output pins output as low, otherwise, if S is low, for each set of pins starting with the same number, Y is equal to I0, otherwise, if S is high, then Y is equal to I1.

Function table (L/H/X = low/high/irrelevant):

/E S I0 I1 Y
H X X X L
L L L X L
L L H X H
L H X L L
L H X H H

References