DM74AS244WM

Overview

The DM74AS244WM is an octal 3-STATE non-inverting bus driver manufactured by onsemi, utilizing the Advanced Schottky logic family. 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 eight buffers with a common enable gate, housed in a 20-Lead Small Outline Integrated Circuit (SOIC) package. Key electrical characteristics include a high-level output current of -15 mA and a low-level output current of 64 mA. Propagation delays are specified at 6.5 ns for LOW-to-HIGH transitions and 5.7 ns for HIGH-to-LOW transitions.

Feature Summary

• Advanced oxide-isolated, ion-implanted Schottky TTL process provides improved switching performance with reduced power dissipation compared to standard Schottky counterparts.
• Functional and pin-compatible with 74LS and Schottky counterpart devices, facilitating direct upgrades in existing designs.
• Capable of driving terminated transmission lines down to 133 Ω due to low impedance output characteristics.
• Specified to interface directly with CMOS logic families when the output high voltage meets the VCC minus 2V threshold.

Applications

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

Procurement Notes

Verify that the component corresponds to the DM74AS244WM part number specifically. Confirm the SOIC-20 package type matches the M20B designation. Ensure the manufacturer origin aligns with onsemi or Fairchild Semiconductor specifications. Check RoHS compliance status against current regulatory requirements before finalizing procurement orders.

Selection Notes

Select this component when bidirectional or unidirectional buffering is required for memory or microprocessor buses. It is suitable for applications needing drive capability for terminated transmission lines. Consider the 0°C to +70°C operating temperature range for environmental constraints. Verify compatibility with existing 74LS or Schottky footprints if replacing legacy components.

Part Context

This device belongs to the DM74AS24x family of Advance Schottky 3-STATE Bus circuits. It shares functional similarities with the DM74AS240 but differs in polarity; the DM74AS244 is non-inverting while the DM74AS240 is inverting. Both utilize the same 20-pin package options and share the Advanced Schottky technology platform for high-speed operation.

Replacement Considerations

The SN74AS240AN is listed as a parameter equivalent substitute. Note that the SN74AS240AN is an inverting driver, whereas the DM74AS244WM is non-inverting. Direct substitution requires verifying signal inversion requirements in the circuit design.

FAQ

Is the DM74AS244WM compatible with 74LS logic?

Yes, the datasheet states it is functionally and pin-compatible with 74LS and Schottky counterparts.

What is the maximum low-level output current?

The maximum low-level output current (IOL) is 64 mA.