The CD74HCT138E is a 3-to-8 high speed CMOS Decoder/Demultiplexer well suited to memory address decoding or data routing applications. It features low power consumption usually associated with CMOS circuitry, yet have speeds comparable to low power Schottky TTL logic. It has three binary select inputs (A0, A1 and A2). If the device is enabled, these inputs determine which one of the eight normally high outputs of the HCT138 series will go low. Two active low and one active high enables (E1\, E2\ and E3) are provided to ease the cascading of decoders. The decoder"s 8 outputs can drive 10 low power Schottky TTL equivalent loads.
I/O Port or memory selector
Three enable inputs to simplify cascading
Balanced propagation delay and transition times
Significant power reduction compared to LSTTL logic ICs