DM74AS240N

Overview

The DM74AS240N is an octal 3-STATE bus driver manufactured by onsemi, housed in a 20-PDIP package. It operates within a supply voltage range of 4.5V to 5.5V and supports a free air operating temperature from 0°C to 70°C. The device features two independent four-bit buffers with common 3-STATE enable gates. Electrical characteristics include a high-level output current of -15mA and a low-level output current of 64mA. Propagation delays are specified at maximum 6.5ns for LOW-to-HIGH transitions and 5.7ns for HIGH-to-LOW transitions under standard test conditions.

Feature Summary

• Advanced oxide-isolated, ion-implanted Schottky TTL process
• Improved switching performance with reduced power dissipation compared to standard Schottky counterparts
• Functional and pin-compatible with 74LS and Schottky logic families
• Capable of driving terminated transmission lines down to 133 ohms

Applications

• Memory system buffer interfaces
• Microprocessor system data routing
• Communication systems signal buffering

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm the specific ordering code matches the required package type, as variants exist in SOIC and PDIP formats. Check for RoHS compliance status and environmental certifications relevant to your manufacturing standards. Ensure the part number suffix corresponds exactly to the desired physical package dimensions and lead finish specifications.

Selection Notes

Select this component when bidirectional or unidirectional buffering is required for memory or communication buses. It serves as a functional replacement for legacy 74LS and standard Schottky devices where higher speed and lower power consumption are necessary. Consider the 20-pin DIP form factor for through-hole mounting requirements. Evaluate the 3-STATE control capabilities for managing multiple drivers on shared data lines effectively.

Part Context

This device belongs to the Advance Schottky (AS) logic family, designed for high-speed digital applications. It is part of a broader series that includes the non-inverting DM74AS244 variant. Originally developed by Fairchild Semiconductor, production rights were transferred to onsemi. The AS series represents a significant evolution in TTL technology, offering superior performance metrics over earlier generations while maintaining compatibility with existing system designs.

Replacement Considerations

SN74AS240AN by Texas Instruments is documented as a parameter-equivalent substitute.