Overview: Octal D-Type Latch with 3-State Output MC74VHC573, MC74VHCT573A The MC74VHC573/MC74VHCT573A is an advanced high speed CMOS octal latch with 3−state output fabricated with silicon gate CMOS technology. It achieves high speed operation similar to equivalent Bipolar Schottky TTL while maintaining CMOS low power dissipation.
The 8−bit D−type latch is controlled by a latch enable input and an output enable input. When the output enable input is high, the eight outputs are in a high impedance state.
The MC74VHC573 inputs are compatible with standard CMOS levels while the MC74VHCT573A inputs are compatible with TTL levels. The MC74VHCT573A device 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 composed of three stages, including a buffer output which provides high noise immunity and stable output. The MC74VHC573 and MC74VHCT573A inputs tolerate voltages up to 5.5 V, allowing the interface of 5 V systems to 3 V systems.
The MC74VHCT573A 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.
