The MC74VHCT245A is an advanced high speed CMOS octal bus transceiver fabricated with silicon gate CMOS technology. It achieves high speed operation similar to equivalent Bipolar Schottky TTL while maintaining CMOS low power dissipation.
It is intended for two-way asynchronous communication between data buses. The direction of data transmission is determined by the level of the DIR input. The output enable pin (OE) can be used to disable the device, so that the buses are effectively isolated.
All inputs are equipped with protection circuits against static discharge.
The VHCT inputs are compatible with TTL levels. This device can be used as a level converter for interfacing 3.3V to 5.0V, because it has full 5V CMOS level output swings.
The VHCT245A input and output (when disabled) structures provide protection when voltages between 0V and 5.5V are applied, regardless of the supply voltage. These input and output structures help prevent device destruction caused by supply voltage - input/output voltage mismatch, battery backup, hot insertion, etc.

• High Speed: t
• = 4.9ns (Typ) at V
• = 5V
• Low Power Dissipation: I
• = 4µA (Max) at T
• = 25 C
• High Noise Immunity: V
• = V
• = 28% V
• Power Down Protection Provided on Inputs and Outputs
• Balanced Propagation Delays
• Designed for 2V to 5.5V Operating Range
• Low Noise: V
• = 1.2V (Max)
• Pin and Function Compatible with Other Standard Logic Families
• Latchup Performance Exceeds 300mA
• ESD Performance: HBM > 2000V; Machine Model > 200V
• Chip Complexity: 304 FETs or 76 Equivalent Gates
• Application Notes
• Do not force a signal on an I/O pin when it is an active output,
• damage may occur.
• All floating (high impedance) input or I/O pins must be fixed by
• means of pull up or pull down resistors or bus terminator ICs.
• A parasitic diode is formed between the bus and VCC terminals.
• Therefore, the VHC245 cannot be used to interface 5V to 3V systems
• directly.
• Pb-Free Packages are Available*