The MC74VHCT157A is an advanced high speed CMOS quad 2-channel multiplexer fabricated with silicon gate CMOS technology. It achieves high speed operation similar to equivalent Bipolar Schottky TTL while maintaining CMOS low power dissipation.
It consists of four 2-input digital multiplexers with common select (S) and enable (Ebar) inputs. When Ebar is held High, selection of data is inhibited and all the outputs go Low.
The select decoding determines whether the A or B inputs get routed to the corresponding Y outputs.
The VHCT inputs are compatible with TTL levels. This device can be used as a level converter for interfacing 3.3 V to 5.0 V because it has full 5 V CMOS level output swings.
The VHCT157A input structures provide protection when voltages between 0 V and 5.5 V are applied, regardless of the supply voltage. The output structures also provide protection when V
= 0 V. These input and output structures help prevent device destruction caused by supply voltage input/output voltage mismatch, battery backup, hot insertion, etc.
The internal circuit is composed of three stages, including a buffer output which provides high noise immunity and stable output. The inputs tolerate voltages up to 7V, allowing the interface of 5V systems to 3V systems.

• High Speed: t
• = 4.1ns (Typ) at V
• = 5V
• Low Power Dissipation: I
• = 4
• A (Max) at T
• = 25°C
• TTL-Compatible Inputs: V
• = 0.8 V; V
• = 2.0 V
• Power Down Protection Provided on Inputs and Outputs
• Balanced Propagation Delays
• Designed for 2V to 5.5V Operating Range
• Low Noise: V
• = 0.8V (Max)
• Pin and Function Compatible with Other Standard Logic Families
• Latchup Performance Exceeds 300mA
• ESD Performance: HBM > 2000V; Machine Model > 200V
• Chip Complexity: 82 FETs or 20 Equivalent Gates
• Pb-Free Packages are Available*