MC74ACT139N

Overview

The MC74ACT139N is a high-speed dual 1-of-4 decoder/demultiplexer manufactured by onsemi. It contains two independent decoders, each accepting two binary weighted address inputs (A0-A1) and providing four mutually exclusive active-LOW outputs (O0-O3). Each decoder features an active-LOW enable input that can function as a data input for demultiplexing applications. The device operates within a supply voltage range of 4.5 V to 5.5 V and supports TTL-compatible inputs.

Feature Summary

• Contains two completely independent 1-of-4 decoders with active-LOW mutually exclusive outputs
• Features TTL compatible inputs for direct interfacing with standard logic families
• Outputs are capable of sourcing and sinking up to 24 mA
• Each half generates all four minterms of two variables for function generation

Applications

• Address decoding in microprocessor systems
• Data distribution via demultiplexing operations
• Logic function generation using minterm outputs
• Memory chip select circuitry

Procurement Notes

Verify the specific ordering suffix 'N' corresponds to the PDIP-16 package configuration when procuring. Confirm that the component meets Pb-free requirements if environmental compliance is necessary for the assembly process. Ensure the supply voltage provided matches the 4.5 V to 5.5 V operating range specified for the ACT series.

Selection Notes

Select this component when a design requires two separate 1-of-4 decoding functions within a single integrated circuit. The ACT series is appropriate for applications needing TTL-compatible input thresholds while maintaining CMOS output drive capabilities. Consider the PDIP-16 package only if through-hole mounting is required for the specific hardware constraints.

Part Context

This part belongs to the MC74AC/ACT139 family of dual 1-of-4 decoders and demultiplexers produced by onsemi. The 'ACT' designation indicates compatibility with TTL input levels, distinguishing it from the standard AC series which utilizes CMOS thresholds. The 'N' suffix specifically identifies the 16-lead Plastic Dual In-line Package (PDIP) variant.

Replacement Considerations

MC74AC139N

FAQ

Can the Enable input be used as a data input?

Yes, the active-LOW Enable input can be utilized as the data input for a 4-output demultiplexer application.

What is the output state when the Enable input is HIGH?

When the Enable input is HIGH, all four outputs are forced HIGH regardless of the address inputs.