ON Semiconductor 74AC257: Quad 2-Input Multiplexer with 3-State Outputs

The ON Semiconductor 74AC257 is a high-performance, quad 2-input multiplexer with 3-state outputs that is designed to meet the demands of high-speed switching applications. This integrated circuit is part of ON Semiconductor's AC series of logic devices, known for their robust performance and compatibility with a wide range of digital systems.

The 74AC257 features four individual 2-input multiplexers with common select and enable inputs. Each multiplexer has two data inputs (A and B), one select input (S), and one output (Y). The select input determines which data input is connected to the output: when S is low, the A input is selected, and when S is high, the B input is selected.

One of the key features of the 74AC257 is its 3-state outputs, which allow the outputs to be set to a high impedance (Z) state. This high impedance state is crucial for creating bus-oriented systems where multiple outputs can be connected to a common bus without interference, as only one device should actively drive the bus at any given time. The outputs are placed in the high impedance state when the enable input (G) is high, regardless of the select and data inputs.

Constructed with advanced CMOS technology, the 74AC257 offers low power dissipation yet high-speed operation. It is capable of operating at speeds comparable to low power Schottky TTL circuits while maintaining CMOS low power consumption. The device operates over a broad voltage range of 2V to 6V and provides TTL compatibility over this range.

With its wide operating voltage range and high noise immunity, the 74AC257 is suitable for a variety of applications, including data routing, signal gating, and multiplexing in systems that require high-speed, low-power digital logic. It is available in various package options, making it flexible for different types of circuit board layouts.

For detailed specifications, timing diagrams, and more information, designers and engineers are encouraged to consult the official ON Semiconductor datasheets and product guides to ensure proper integration of the 74AC257 into their projects.