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;" | |||
! /E !! S !! I0 !! I1 !! style="border-left:3px double" |Y | |||
|- | |||
| H || X || X || X || style="border-left:3px double" |L | |||
|- | |||
| L || L || L || X || style="border-left:3px double" |L | |||
|- | |||
| L || L || H || X || style="border-left:3px double" |H | |||
|- | |||
| L || H || X || L || style="border-left:3px double" |L | |||
|- | |||
| L || H || X || H || style="border-left:3px double" |H | |||
|} | |||
== References == | |||
* [https://www.ti.com/product/SN74LS157 TI - SN74LS157] | |||
[[Category:7400 series|157]] | [[Category:7400 series|157]] | ||
Latest revision as of 18:09, 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 |
