DM74ALS244AWM

Overview

The DM74ALS244AWM is an octal 3-STATE bus driver manufactured by onsemi, housed in a 20-Lead Small Outline Integrated Circuit (SOIC) package. It operates within a supply voltage range of 4.5V to 5.5V and supports an operating temperature range of 0°C to +70°C. The device features two separate groups of four buffers with independent control inputs that enable outputs when set logic LOW. Key electrical characteristics include a propagation delay time of 3ns to 10ns from input A to output Y, and an output drive current capability of -15mA for high level and 24mA for low level.

Feature Summary

• Provides flexibility in implementing bus interfaces for memory, microprocessor, or communication systems.
• Features 3-STATE circuitry that maintains buffer outputs in high impedance during power supply ramp-up or ramp-down to eliminate bus glitching.
• Utilizes PNP input design to reduce input loading.

Applications

• Memory system bus interfacing
• Microprocessor system data routing
• Communication system signal transmission

Procurement Notes

Verify the specific ordering code suffix against the manufacturer's documentation to ensure the correct package type, as the base part number may correspond to multiple physical packages such as SOIC, SOP, SSOP, or PDIP. Confirm that the required temperature grade aligns with the standard commercial range or if extended temperature variants are necessary for the application environment.

Selection Notes

Select this component when designing systems requiring octal bus drivers with 3-STATE capabilities. Ensure the design accommodates the dual-group control structure where each group of four buffers has its own enable input. Verify that the load conditions fall within the specified switching response parameters of 500Ω resistance and 50pF capacitance for guaranteed performance across the full temperature and supply voltage range.

Part Context

This device belongs to the Advanced Low Power Schottky (ALS) TTL logic family, offering improved switching performance with less power dissipation compared to the 74LS counterpart. It is functionally and pin compatible with 74LS devices, facilitating direct upgrades in existing designs. The product line includes various package options including SOIC, SOP, SSOP, and PDIP to suit different mounting requirements.

Replacement Considerations

The datasheet indicates functional and pin compatibility with the 74LS counterpart. Designers should verify that the target replacement device meets the specific ALS electrical characteristics, particularly the output drive currents and propagation delays, rather than relying solely on pin compatibility.