Układy CMOS i TTL

74138 – Dekoder/demultiplekser z 3 linii na 8 linii

     +---+--+---+            +---+----+----+---+---+---*---+---+---+---+
  S0 |1  +--+ 16| VCC        |EN1|/EN2|/EN3| S2| S1| S0|/Y0|/Y1|...|/Y7|
  S1 |2       15| /Y0        +===+====+====+===+===+===*===+===+===+===+
  S2 |3       14| /Y1        | 0 | X  |  X | X | X | X | 1 | 1 | 1 | 1 |
/EN3 |4   74  13| /Y2        | 1 | 1  |  X | X | X | X | 1 | 1 | 1 | 1 |
/EN2 |5  138  12| /Y3        | 1 | 0  |  1 | X | X | X | 1 | 1 | 1 | 1 |
 EN1 |6       11| /Y4        | 1 | 0  |  0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 |
 /Y7 |7       10| /Y5        | 1 | 0  |  0 | 0 | 0 | 1 | 1 | 0 | 1 | 1 |
 GND |8        9| /Y6        | 1 | 0  |  0 | . | . | . | 1 | 1 | . | 1 |
     +----------+            | 1 | 0  |  0 | 1 | 1 | 1 | 1 | 1 | 1 | 0 |
                             +---+----+----+---+---+---*---+---+---+---+