The MC74VHC257 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 (OE)bar inputs. When (OE)bar 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 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
• High Noise Immunity: V
• = V
• = 28% V
• Power Down Protection Provided on Inputs
• 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: FETs = 100; Equivalent Gates = 25
• These devices are available in Pb-free package(s). Specifications herein apply to both standard and Pb-free devices. Please see our website at www.onsemi.com for specific Pb-free orderable part numbers, or contact your local ON Semiconductor sales office or representative.