DM74AS244SJ

Overview

The DM74AS244SJ is an octal 3-state non-inverting buffer manufactured by onsemi, utilizing the Advanced Schottky process. 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 high-impedance inputs and low-impedance outputs capable of driving terminated transmission lines down to 133 ohms. It provides a maximum output current of 64mA in the low state and -15mA in the high state. Propagation delays are specified at approximately 6.5ns for low-to-high transitions and 5.7ns for high-to-low transitions under standard load conditions.

Feature Summary

• Advanced oxide-isolated, ion-implanted Schottky TTL process for improved switching performance with reduced power dissipation compared to standard Schottky counterparts.
• Functional and pin-compatible with 74LS and Schottky logic families, facilitating direct upgrades in existing designs.
• Capable of interfacing directly with CMOS devices when the output high level meets the VCC minus 2V specification.
• Designed to drive terminated transmission lines with low impedance outputs while maintaining high impedance inputs to minimize line loading.

Applications

• Memory system bus buffering
• Microprocessor interface circuits
• Communication systems signal routing

Procurement Notes

Verify the specific suffix 'SJ' against official manufacturer documentation, as datasheets typically list 'WM' (SOIC) or 'N' (PDIP). Confirm RoHS compliance status and lead-free availability through current onsemi channels. Check component obsolescence status, as this series may be discontinued. Ensure the ordering code matches the required package type and tape/reel options if applicable.

Selection Notes

Select this component for applications requiring fast propagation delays and high drive capability in 5V logic environments. It serves as a suitable replacement for legacy 74LS244 designs where speed is critical. Consider the thermal characteristics and package constraints during PCB layout. Verify that the input and output voltage levels align with the connected CMOS or TTL components in the system architecture.

Part Context

This part belongs to the DM74AS family of Advance Schottky logic devices produced originally by Fairchild Semiconductor, now part of onsemi. The AS series offers significantly faster switching speeds than standard LS logic while consuming less power than older Schottky variants. The DM74AS244 specifically provides eight non-inverting buffers with 3-state control, distinct from the inverting DM74AS240 variant.

Replacement Considerations

SN74AS240AN: Parameter equivalent from Texas Instruments. SN74BCT240N: Parameter equivalent from Texas Instruments. SN74F240N: Parameter equivalent from Texas Instruments.