SN74LS157DR

Overview

The SN74LS157DR is a quad 2-input data selector/multiplexer from the Texas Instruments 74LS series. It features four independent multiplexers with common select and enable inputs, allowing selection between two data sources for four bits. The device provides non-inverting outputs and utilizes Schottky barrier diode process technology for high-speed operation. It operates within a supply voltage range of 4.75 V to 5.25 V and supports surface-mount installation in SOIC-16 packages.

Feature Summary

• Quad configuration providing four independent 2-to-1 multiplexing channels
• Common select and enable inputs control all four channels simultaneously
• Non-inverting output structure presents selected data in true form
• Schottky process fabrication ensures high-speed switching performance

Applications

• Data routing between multiple sources in digital systems
• Signal selection in microprocessor-based interfaces
• Generation of specific logic functions using variable inputs

Procurement Notes

Verify the package type matches the required PCB footprint, specifically confirming the SOIC-16 narrow variant. Ensure the operating temperature range aligns with the application environment, as standard LS series devices typically support commercial temperatures. Confirm RoHS compliance status if environmental regulations apply to the final assembly. Cross-reference the manufacturer part number with distributor listings to ensure authenticity and correct revision level.

Selection Notes

Select this component when a quad multiplexer with common control lines is required for LSTTL compatibility. It is suitable for designs needing high-speed switching within standard TTL voltage levels. Consider alternative families like HC or ACT if lower power consumption or wider voltage ranges are necessary. Verify that the input clamp diodes and glitch-free multiplexing features meet the signal integrity requirements of the target circuit.

Part Context

This device belongs to the widely used 74LS (Low-power Schottky) logic family, known for balancing speed and power dissipation. It serves as a standard MSI component for digital logic applications requiring data selection. The DR suffix indicates a tape-and-reel surface-mount packaging format, facilitating automated assembly processes in high-volume manufacturing environments.

Replacement Considerations

Compatible substitutes include SN74LS157N and SN74LS157D from various manufacturers such as Motorola and ON Semiconductor. These parts share identical pinouts and logical functionality, ensuring direct replacement in existing designs without circuit modification.