MC74HC240ADW

Overview

The MC74HC240ADW is an octal 3-state inverting buffer and line driver manufactured by onsemi. It operates within a supply voltage range of 2.0 V to 6.0 V and features two active-low output enables. The device provides high noise immunity and low input current characteristics typical of CMOS technology. Propagation delays vary from 14 ns at 6.0 V to 80 ns at 2.0 V. It supports up to 15 LSTTL loads and is housed in a SOIC-20 package.

Feature Summary

• Octal configuration with dual active-low output enables for flexible bus management
• Inverting outputs compatible with standard CMOS, NMOS, and TTL logic families
• High noise immunity and low input leakage current inherent to silicon-gate CMOS design

Applications

• Memory address drivers
• Clock drivers
• Sub-oriented systems requiring bus isolation

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm package type and shipping quantity. Ensure the selected variant meets all environmental compliance requirements such as RoHS standards. Confirm that the component's moisture sensitivity level aligns with your assembly process capabilities before procurement.

Selection Notes

Select this component when an octal inverting buffer with 3-state capability is required for bus applications. Consider the operating voltage range and propagation delay specifications relative to system timing constraints. Verify compatibility with existing logic families and ensure adequate thermal dissipation for the chosen package style.

Part Context

This part belongs to the MC74HC240A series of high-performance silicon-gate CMOS logic devices. It serves as a direct pinout-compatible replacement for LS240 devices while offering improved power consumption and noise immunity characteristics associated with modern HC family technology.

Replacement Considerations

MC74HC240ADWG

FAQ

How are unused inputs handled?

Unused inputs must not be left open; they should be tied to either a high-logic voltage level or a low-logic input voltage level.

What is the function of Enable A and Enable B?

These pins are active-low output enables. Applying a low level enables the outputs as inverters, while a high level places them in a high-impedance state.