DM74ALS138N – FSC

Overview

The onsemi DM74ALS138N is a high-speed 1-of-8 decoder/demultiplexer designed to translate a 3-bit binary input into one of eight mutually exclusive outputs. Its primary function is to enable selective activation of one output line based on the binary address presented at its select inputs, crucial for address decoding in memory systems or controlling multiple peripheral devices. A key design consideration for this TTL-compatible device is managing the propagation delay versus power consumption trade-off; while the ALS family offers reduced power compared to standard TTL, careful layout is still necessary to mitigate timing skew in high-speed applications, especially when driving capacitive loads.

Key Features

• Type: Decoder/Demultiplexer
• Circuit: 1 x 3:8
• Supply Voltage: 4.5V to 5.5V
• Output Drive: 400µA (High), 8mA (Low)
• Operating Temperature: 0°C to 70°C
• Package: 16-DIP (0.300″ width)

Applications

The component is engineered for deployment in systems requiring high reliability and performance under specific operating conditions. It provides functional stability across the stated design envelope.

• Address decoding for RAM/ROM selection in embedded systems
• Peripheral device selection in microcontroller-based designs
• Control signal generation for multiplexed data buses
• Output gating for sequential logic circuits