SN74LS399NS Texas Instruments Integrated Circuit (Dual-In-Line Packages) In Stock
The SN74LS399NS is a Quad 2-Port Register from Texas Instruments, housed in a 16-pin PDIP package. It integrates four D-type flip-flops with a common select input to choose between two data sources, supporting 5V TTL logic systems. Available in stock worldwide with fast shipping.
- Manufacturer
- Texas Instruments
- Package
- Dual-In-Line Packages
- Pin Count
- 16
- Lifecycle
- ACTIVE
- Datasheet
- SN74LS399NS Datasheet PDF
- Category
- Integrated Circuit
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Quad 2-port register with common source select input allowing multiplexed data loading from two independent input ports
- Standard 5V TTL logic compatibility for seamless integration into established LS-series digital logic designs
- 16-pin PDIP through-hole package provides easy hand-soldering and breadboard prototyping for system development
- Synchronous clocking of all four flip-flops ensures predictable, glitch-free data capture in registered bus designs
Applications
The SN74LS399NS is used in digital systems requiring multiplexed data selection and storage, such as CPU bus arbitration, data routing, and register file implementations. Its dual-port input with common select line makes it suitable for applications where two data sources share a common register bank. It is widely found in legacy digital logic designs, embedded controllers, and industrial electronic equipment operating on 5V TTL logic.
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What is the SN74LS399NS and what does it do?
The SN74LS399NS is a Quad 2-Port Register that contains four D-type flip-flops, each with two data inputs and a common source-select signal. The select input determines which of the two data ports is loaded into the register on a clock edge, making it a useful element in multiplexed data bus designs.
What package type does the SN74LS399NS use?
The SN74LS399NS comes in a 16-pin Plastic Dual In-Line Package (PDIP), a through-hole format ideal for prototyping, manual assembly, and legacy PCB designs. The PDIP package allows for easy installation in standard 0.1-inch pitch IC sockets.
What logic family does the SN74LS399NS belong to and what is its supply voltage?
The SN74LS399NS belongs to Texas Instruments' 74LS (Low-power Schottky TTL) logic family and operates from a standard 5V supply. It provides TTL-compatible logic levels and is fully interoperable with other 74LS, 74S, and 74ALS series devices.
What are typical applications for the SN74LS399NS?
This quad 2-port register is used for data multiplexing, bus switching, and register-based storage in 5V TTL digital systems. Common applications include CPU data path registers, address bus multiplexers, and state machine storage elements in legacy embedded and industrial control designs.
Is the SN74LS399NS still available and what are its alternatives?
The SN74LS399NS may be approaching end-of-life in some markets, but stock is available from distributors worldwide. Functional alternatives include the SN74LS399D (SOIC-16 package) or similar quad register devices from the 74HC or 74HCT families if 5V CMOS compatibility is acceptable.
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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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