Overview: DATA SHEET .onsemi. Octal Bus Buffer/Line Driver Inverting with 3−State Outputs MC74VHC240, MC74VHCT240A The MC74VHC240/MC74VHCT240A is a high speed CMOS octal bus buffer fabricated with silicon gate CMOS technology. The device achieves high speed operation similar to equivalent Bipolar Schottky TTL while maintaining CMOS low power dissipation.
The MC74VHC240/MC74VHCT240A is an inverting 3−state buffers with two active−low output enables. The device is designed to drive bus lines or buffer memory address registers.
The MC74VHC240 inputs are patible with standard CMOS levels while the MC74VHCT240A inputs are patible with TTL levels. The MC74VHCT240A can be used as a level converter for interfacing 3.3 V to 5.0 V, because it has full 5.0 V CMOS level output swings.
The internal circuit is posed of three stages, including a buffer output which provides high noise immunity and stable output. The MC74VHC240 and MC74VHCT240A input structures tolerate voltages up to 5.5 V, allowing the interface of 5 V systems to 3 V systems.
The MC74VHCT240A output structures provide protection when VCC = 0 V. These output structures help prevent device destruction caused by supply voltage − input/output voltage mismatch, battery backup, hot insertion, etc.
