SN74AS138 - Texas Instruments

SN74AS138 3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS

The ′ALS138A and ′AS138 are 3-line to 8-line decoders/demultiplexers designed for highperformance memory-decoding or data-routing applications requiring very short propagation delay times. In high-performance systems, these devices can be used to minimize the effects of system decoding. When employed with high-speed memories with a fast enable circuit, the d.

Features

m decoder is negligible. SN54ALS138A, SN54AS138 . . . J PACKAGE SN74ALS138A, SN74AS138 . . . D OR N PACKAGE (TOP VIEW) A1 B2 C3 G2A 4 G2B 5 G1 6 Y7 7 GND 8 16 VCC 15 Y0 14 Y1 13 Y2 12 Y3 11 Y4 10 Y5 9 Y6 SN54ALS138A, SN54AS138 . . . FK PACKAGE (TOP VIEW) Y0 VCC NC A B C G2A NC G2B G1 3 2 1 20 19 4 18 Y1 5 17 Y2 6 16 NC 7 15 Y3 8 14 Y4 9 10 11 12 13 Y5 Y6 NC GND Y7 The conditions at the binary-select (A, B, and C) inputs and the three enable (G1, G2A, and G2B) inputs select one of eight output lines. Two NC
  – No internal connection active-low and one active-high .