Product Overview: 74AHCT257D by NXP Semiconductors

The 74AHCT257D is a high-speed Si-gate CMOS device and is pin compatible with Low-power Schottky TTL (LSTTL). It is specified in compliance with JEDEC standard no. 7A. The 74AHCT257D is a quad 2-input multiplexer with 3-state outputs that combine the advantages of the high-speed CMOS technology with the functionality of the industry standard 74 series logic.

Key Features

• Logic Type: Quad 2-Input Multiplexer
• Supply Voltage Range: 4.5V to 5.5V
• Output Capability: Bus Driver
• IC Output Type: Tri-State, Non-Inverted
• Propagation Delay: 8.5ns at 4.5V
• Operating Temperature Range: -40°C to +125°C
• Package Type: SOIC
• Pin Count: 16
• Logic Case Style: SO
• Mounting Type: Surface Mount

Functional Description

The 74AHCT257D is designed for multiplexing digital or analog signals. It features four identical 2-input multiplexers with three-state outputs that can be connected directly to a bus line. Each multiplexer has two select inputs (S0 and S1), four data inputs (A0 to A3, B0 to B3), and an output enable (OE) input. The select inputs determine which of the data inputs are allowed to propagate to the output.

When the output enable (OE) input is low, the selected data input appears at the output. When OE is high, the output goes into a high-impedance state, effectively disconnecting the output from the bus line. This feature makes the 74AHCT257D ideal for interfacing with bus lines in a bus-organized system.

Applications

With its high-speed performance and bus driver capability, the 74AHCT257D is suitable for a wide range of applications, including:

• Bus multiplexing
• Signal gating
• Backplane driving
• Data routing
• Function generation

Given its robustness and versatility, the 74AHCT257D from NXP is an excellent choice for designers looking for a reliable multiplexer solution in their digital systems.