DM74LS244WM

Overview

The DM74LS244WM is an octal 3-state buffer and line driver manufactured by onsemi, originally produced under Fairchild Semiconductor. It features two independent buffers with non-inverting logic and three-state outputs. The device operates within a supply voltage range of 4.75V to 5.25V and supports a free-air operating temperature from 0°C to +70°C. Key electrical characteristics include a typical low-level output current of 24mA and a high-level output current of -15mA. Propagation delays are typically 10.5ns for inverting paths and 12ns for non-inverting paths at VCC = 5V.

Feature Summary

• Features PNP data line inputs that reduce DC loading on bus lines while providing improved noise rejection through hysteresis.
• Provides 3-state outputs capable of driving bus lines directly or terminated lines down to 133Ω impedance.
• Designed to enhance performance and printed circuit board density when used as memory-address drivers, clock drivers, or bus-oriented transmitters.

Applications

• Memory-address drivers
• Clock drivers
• Bus-oriented transmitters and receivers

Procurement Notes

Verify the manufacturer origin, as this component was originally a Fairchild Semiconductor product now managed by onsemi. Confirm the package type matches the M20B designation for the 20-lead SOIC variant. Check RoHS compliance status against specific ordering codes, as older manufacturing runs may differ. Ensure the application environment stays within the specified commercial temperature range of 0°C to +70°C.

Selection Notes

Select this component for applications requiring octal buffering with high fanout capabilities and noise immunity. The PNP input structure offers advantages over standard TTL inputs regarding DC loading. Consider the 3-state functionality for multiplexed bus systems. Verify that the 5V logic level compatibility aligns with the system design requirements before integration.

Part Context

This part belongs to the 74LS series of logic integrated circuits, specifically the octal buffer family. It serves as a digital interface component for managing signal integrity across multiple lines. The device is distinct from HC or HCT variants due to its specific LS technology characteristics and power consumption profile.

Replacement Considerations

Direct substitutes include other octal 3-state buffers from the 74LS family such as the SN74LS244. Verify pin compatibility and electrical specifications like propagation delay and output drive strength when cross-referencing alternative manufacturers.