Combines Decoder and 3-Bit Address
Latch
Incorporates Two Output Enables to
Simplify Cascading
Package Options Include Plastic Small-
Outline (D) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil DIPs

description
The SN54ALS137A, SN74ALS137A, and
SN74AS137 are 3-line to 8-line decoders/
demultiplexers with latches on the three address
inputs. When the latch-enable (LE) input is low,
the devices act as decoders/demultiplexers.
When LE goes from low to high, the address
present at the select (A, B, and C) inputs is stored
in the latches. Further address changes are
ignored as long as LE remains high. The
output-enable controls (G1 and G2) control the
outputs independently of the select or
latch-enable inputs. All of the outputs are forced
high if G1 is low or G2 is high. These devices are
ideally suited for implementing glitch-free
decoders in strobed (stored-address) applications
in bus-oriented systems.
The SN54ALS137A is characterized for operation
over the full military temperature range of −55°C
to 125°C. The SN74ALS137A and SN74AS137
are characterized for operation from 0°C to 70°C.