DM74S139N

Overview

The DM74S139N is a dual 2-line-to-4-line decoder/demultiplexer manufactured by onsemi, housed in a 16-lead Plastic Dual-In-Line (PDIP) package. It operates within a supply voltage range of 4.75V to 5.25V and supports an operating temperature range of 0°C to +70°C. The device features Schottky clamping for high performance, with typical propagation delays of 7.5ns from select inputs to outputs and up to 14ns from enable inputs to outputs under standard load conditions.

Feature Summary

• Contains two fully independent 2-to-4-line decoders or demultiplexers within a single package
• Schottky-clamped inputs suppress line-ringing and simplify system design
• Fully buffered inputs present only one normalized load to the driving circuit
• Active-LOW enable input can function as a data line in demultiplexing applications

Applications

• High-performance memory decoding systems
• Data routing and transmission systems
• Cascading logic expansion requiring minimal external gates

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm that the specific order matches the DM74S139N designation and PDIP-16 package type. Review datasheet specifications regarding absolute maximum ratings and recommended operating conditions to ensure compatibility with target system voltages and environmental requirements before finalizing procurement.

Selection Notes

Select this component when designing circuits requiring dual independent decoding paths within a limited footprint. The Schottky technology provides faster switching speeds compared to standard TTL variants. Ensure the application environment remains within the specified 0°C to +70°C temperature range and utilizes a stable 5V power supply to maintain signal integrity and meet timing constraints.

Part Context

This part belongs to the Fairchild Semiconductor DM74S series, which utilizes Schottky transistor logic for enhanced speed. The DM74S139 specifically addresses the need for multiple decoding functions in a compact form factor. It serves as a complementary solution to the DM74S138, offering dual 2-to-4 decoding capabilities rather than a single 3-to-8 configuration.

Replacement Considerations

Direct substitutes include other manufacturers' equivalents such as the SN74S139 from Texas Instruments, provided they adhere to the same PDIP-16 package and electrical characteristics.