The 74LS138 is a 3:8 Decoder IC that is commonly used in decoding or de-multiplexing circuits for memory decoding or data routing purposes. It is designed for high-speed operations and has three enable pins to make it easier to cascade with other ICs. The device decodes 1-of-8 lines, set by x3 binary select inputs & three enable inputs. The LS138 can be used as an 8- output demultiplexer by using one active LOW Enable input as data input & the other Enable inputs as strobes. The IC has an operating voltage from 1.0V to 5.5V with a low power consumption of 32mW. The propagation delay is around 21nS.

Features: 

• Demultiplexing capability
• Designed with Schottky diodes which helps to suppress line-rigging and it makes the design simple
• Multiple Input Enables for parallel expansion
• Has internal ESD Protection
• Designed specifically for high speed: Memory decoders Data transmission systems
• Operating voltage from 1.0V to 5.5V
• Low power consumption of 32mW
• The propagation delay is around 21nS
• Operating Free Air Temperature Range 0°C to +70°C