SN74AS257NS Texas Instruments Integrated Circuit (Small Outline Packages) In Stock
The SN74AS257NS is a quad 2-to-1 data selector/multiplexer with three-state outputs in the high-speed AS logic family operating at 5V. It features active-low output enable control and propagation delays under 5ns for fast data routing in digital systems. Available from Texas Instruments with worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 16
- Lifecycle
- ACTIVE
- Datasheet
- SN74AS257NS Datasheet PDF
- Category
- Integrated Circuit
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Quad 4-channel 2-to-1 multiplexer with three-state outputs enabling bus-sharing in complex digital architectures
- High-speed AS (Advanced Schottky) logic family delivering propagation delays under 5ns for demanding timing budgets
- Active-low output enable pin allowing multiple devices to share a common bus without contention
- 5V TTL-compatible operation ensuring drop-in compatibility with existing 74-series logic designs
Applications
The SN74AS257NS is used in high-speed digital systems for data bus multiplexing, address selection, and signal routing in memory interfaces and microprocessor support circuits. It is well-suited for applications requiring fast switching between two data sources on a shared bus with three-state output control to prevent bus conflicts. The device also serves in FPGA prototyping boards and data acquisition systems where rapid and reliable 2-to-1 signal selection is essential.
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for SN74AS257NS:
Multiplexer, AS Series, 4-Func, 2 Line Input, 1 Line Output, True Output, TTL, PDSO16
Frequently Asked Questions
What is the function of the SN74AS257NS?
The SN74AS257NS is a quad 2-to-1 data selector and multiplexer that routes one of two 4-bit data inputs to the output based on a common select signal, with three-state outputs enabling multiple devices to share a common data bus without signal conflicts.
What logic family does the SN74AS257NS belong to?
The SN74AS257NS belongs to the AS (Advanced Schottky) logic family, which provides significantly faster propagation delays compared to standard TTL logic, making it suitable for high-speed digital circuits requiring sub-5ns switching performance at 5V supply.
What does the three-state output on the SN74AS257NS do?
The three-state outputs allow the SN74AS257NS outputs to be placed in a high-impedance state via an active-low output enable pin, enabling multiple multiplexer devices to share a single data bus by disabling non-active drivers to prevent bus contention.
What package is the SN74AS257NS available in?
The SN74AS257NS is available in a small outline package format, providing a compact surface-mount solution for high-density PCB designs while maintaining the full electrical performance of the AS logic family multiplexer.
What are typical applications for the SN74AS257NS?
Typical applications include data bus multiplexing, address line selection in memory systems, microprocessor bus routing, FPGA interface circuits, and any digital design requiring fast selection between two 4-bit data sources with three-state bus control capability.
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About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
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