1.

General description

The 74LVC138A is a 3-to-8 line decoder/demultiplexer. It accepts three binary weighted

address inputs (A0, A1 and A2) and, when enabled, provides eight mutually exclusive

outputs (Y0to Y7) that are LOW when selected.

There are three enable inputs: two active LOW (E1andE2) and one active HIGH (E3).

Every output will be HIGH unless E1andE2 are LOW and E3 is HIGH.

This multiple enable function allows easy parallel expansion of the device to a 1-of-32

(5 lines to 32 lines) decoder with just four 74LVC138A devices and one inverter. The

74LVC138A can be used as an eight output demultiplexer by using one of the active LOW

enable inputs as the data input and the remaining enable inputs as strobes. Unused

enable inputs must be permanently tied to their appropriate active HIGH or LOW state.

2.

Features and benefits

 transmission lines at 125 C

40 Cto+85 C and from 40 C to +125 C

74LVC138A

3-to-8 line decoder/demultiplexer; inverting

Rev. 5 — 19 October 2011

Product data sheet