MC74AC139D

Overview

The MC74AC139D is a high-speed, dual 1-of-4 decoder/demultiplexer manufactured by onsemi. It features two independent decoders, each accepting two binary weighted address inputs (A0-A1) and providing four mutually exclusive active-LOW outputs (O0-O3). Each decoder includes an active-LOW enable input that can function as a data input for demultiplexing applications or generate minterms of two variables. The device operates within a supply voltage range of 2.0 V to 6.0 V and supports output source/sink currents of 24 mA.

Feature Summary

• Dual independent 1-of-4 decoder architecture with active-LOW mutually exclusive outputs
• Enable input functionality supporting both decoding control and demultiplexing data routing
• High-speed CMOS technology enabling efficient signal processing in logic networks
• Capable of generating all four minterms of two variables for function generation

Applications

• Address decoding in microprocessor systems
• Data distribution via demultiplexing operations
• Implementation of combinational logic functions using minterm generation
• Peripheral selection circuits requiring mutually exclusive output states

Procurement Notes

Verify the specific suffix 'D' corresponds to the SOIC-16 package configuration required for your design. Confirm RoHS compliance status if environmental regulations apply to your manufacturing process. Ensure the ordering part number matches the exact logic family variant needed for your voltage levels. Cross-reference the datasheet revision date to ensure compatibility with current design specifications.

Selection Notes

Select this component when a dual decoder solution is required within a single package to reduce board space. Consider the AC logic family for operation across a wide voltage range from 2V to 6V. Evaluate the 24 mA output drive capability against load requirements. Verify that the SOIC-16 package dimensions fit within the available PCB real estate constraints.

Part Context

This device belongs to the 74AC logic family, known for high-speed performance comparable to standard TTL but with wider voltage tolerance. It serves as a functional replacement for older discrete decoder implementations. The dual configuration allows for consolidated logic design compared to using separate single-decoder ICs.

Replacement Considerations

MC74ACT139D offers TTL-compatible input thresholds while maintaining similar functionality. MC74AC139DT provides the same logical operations in a TSSOP-16 surface-mount package.