CD74HC138 - Texas Instruments

CD74HC138 High-Speed CMOS Logic 3 to 8-Line Decoder/Demultiplexer Inverting/Noninverting

The CDx4HC(T)138 and '238 are three to eight decoders with one standard output strobe (G2) and two active low output strobes (G 1 and G 0). When the outputs are gated by any of the strobe inputs, they are all forced into the high state. When the outputs are not disabled by the strobe inputs, only the selected output is low while all others are high. The CD.

Features

• Select one of eight data outputs:
  – Active low for '138
  – Active high for '238
• l/O port or memory selector
• Three enable inputs to simplify cascading
• Typical propagation delay of 13 ns at VCC = 5 V, CL = 15 pF, TA = 25°C
• Fanout (over temperature range)
  – Bus driver outputs: 15 LSTTL loads
  – Standard outputs: 10 LSTTL loads
• Wide operating temp range: -55°C to 125°C
• Balanced propagation delay and transition times
• Significant power reduction compared to LSTTL logic ICs
• HC types
  – 2 V to 6 V operation
  – High noise immunity: NIL = 30%, NIH = 30% of VCC at VCC = 5 V
• HCT types
  – 4..