SN74AS257NSR

Overview

The SN74AS257NSR is a quadruple 2-input data selector/multiplexer from the Texas Instruments AS logic series, housed in a 16-pin Small Outline Package (SOP). It multiplexes signals from four 2-bit data sources to four output lines. The device features three-state outputs controlled by an output-enable (OE) input; when OE is high, outputs are disabled. It operates within a supply voltage range of 4.5 V to 5.5 V and supports an operating temperature range of 0°C to 70°C.

Feature Summary

• Provides bus interface capability from multiple sources in high-performance systems
• Features three-state outputs that do not load data lines when disabled
• Designed for direct interfacing with system buses

Applications

• Multiplexing signals from 4-bit data sources to 4-output data lines
• Bus-organized system signal routing
• High-performance system bus interface design

Procurement Notes

Verify the specific ordering suffix against the manufacturer's package option addendum to confirm the SOP-16 configuration and tape-and-reel specifications. Ensure the component meets RoHS compliance requirements for the intended application environment. Cross-reference the datasheet revision date to confirm electrical characteristics match current design constraints.

Selection Notes

Select this component for applications requiring fast switching speeds typical of the AS logic family. Compare propagation delay parameters against system timing requirements. Verify that the 3-state output drive capabilities align with the bus loading requirements of the target architecture.

Part Context

This part belongs to the SN74AS257/258 family of data selectors. The SN74AS257 provides non-inverting outputs, while the SN74AS258 provides inverting outputs. Both share identical pinouts and packaging options, differing only in logical inversion at the output stage.

Replacement Considerations

SN74ALS257NSR offers similar functionality with different electrical characteristics.