The DM74LS257BM is a Quad 2-Input Multiplexer with 3-State Outputs manufactured by Fairchild/ON Semiconductor. This device consists of four 2-input multiplexers with common select and enable inputs. When the enable input is low, one of the two inputs is selected based on the select input. When the enable input is high, all outputs are forced to a high-impedance state, allowing multiple devices to share a common bus.

Applications

• Data selection
• Address multiplexing
• Memory mapping
• Parallel-to-serial conversion
• Digital switching

Features

• Four 2-input multiplexers in a single package
• Common select and enable inputs
• 3-state outputs for bus compatibility
• Low power consumption
• High-speed operation

Benefits

• Reduced component count: Consolidates four multiplexers into one package.
• Simplified system design: Common select and enable inputs streamline control logic.
• Increased system flexibility: 3-state outputs allow for easy bus sharing.
• Minimized power dissipation: Low power consumption reduces heat generation.
• Improved system performance: High-speed operation enables faster data transfer.

Additional Details

The DM74LS257BM operates with a supply voltage of 4.75V to 5.25V. The device's outputs are capable of driving up to 15 standard TTL loads. The propagation delay is typically around 15 nanoseconds. The 3-state outputs provide a high-impedance state when the enable input is high, preventing the device from loading the bus when it is not actively selecting data. This multiplexer is commonly used in computer systems, data acquisition systems, and digital communication systems to select and route data efficiently. The operating temperature range is typically 0°C to 70°C. The device is available in a SOIC (Small Outline Integrated Circuit) package.