74ACT139MTC

Signal Switches, Multiplexers, Decoders Overview

The Fairchild Semiconductor 74ACT139MTC is a high-speed, dual 1-of-4 decoder/demultiplexer housed in a 16-TSSOP package. It contains two independent decoders, each accepting two binary weighted inputs (A0–A1) and providing four mutually exclusive active-LOW outputs (O0–O3). Each decoder features an active-LOW enable input. The device operates within a supply voltage range of 4.5 V to 5.5 V and supports a maximum propagation delay of 10.5 ns at 5 V with 50 pF load. It functions reliably across an operating temperature range of -40°C to +85°C.

Signal Switches, Multiplexers, Decoders Feature Summary

• Dual independent 1-of-4 decoding architecture
• Active-LOW output and enable logic
• High-speed CMOS performance

Signal Switches, Multiplexers, Decoders Applications

• Memory decoding systems
• Data routing applications
• Address decoding circuits

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify the specific manufacturer origin, as Fairchild Semiconductor assets were acquired by onsemi. Confirm that the 74ACT139MTC designation corresponds to the original Fairchild production run rather than the onsemi equivalent MC74ACT139 series. Ensure the 16-TSSOP package matches the required footprint for the target PCB design. Check for RoHS compliance documentation specific to the manufacturing date code.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when a dual decoder solution is required in a compact surface-mount form factor. The ACT logic family offers faster switching speeds compared to standard AC or HC families while maintaining compatible pinouts. Verify that the active-LOW output polarity aligns with the downstream circuit requirements. Ensure the 5V supply voltage is stable within the specified 4.5V to 5.5V range for optimal timing performance.

Signal Switches, Multiplexers, Decoders Part Context

This part belongs to the 74ACT logic family, which provides advanced CMOS technology with speed comparable to TTL but lower power consumption. The 74ACT139 specifically addresses the need for multiple decoding channels in a single package. It serves as a functional replacement for older LS139 devices where higher speed is necessary. The TSSOP package allows for denser board layouts compared to traditional DIP packages.

Signal Switches, Multiplexers, Decoders Replacement Considerations

The onsemi MC74ACT139DR2G is a documented equivalent offering identical logical functionality. Verify pin compatibility and electrical specifications before substitution. Note that packaging differences may exist between the MTC and DR2G suffixes.