SN74HC139NS Texas Instruments Integrated Circuit (Small Outline Packages) In Stock
The SN74HC139NS is a dual 2-to-4 line decoder and demultiplexer from Texas Instruments in a 16-pin SOP package, featuring active-low outputs, individual enable inputs per decoder section, and HC CMOS logic operating from 2 V to 6 V supply. It is used for address decoding, chip-select generation, and data routing in microprocessor, FPGA, and memory expansion circuits.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 16
- Lifecycle
- ACTIVE
- Datasheet
- SN74HC139NS Datasheet PDF
- Category
- Integrated Circuit
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
What are the key features of SN74HC139NS?
- Dual independent 2-to-4 line decoder/demultiplexer
- Active-low outputs with individual enable per section
- HC CMOS: operates from 2 V to 6 V supply
- Propagation delay typically 7 ns at 5 V
- 16-pin SOP package for compact SMT assembly
- TTL-compatible input thresholds for mixed-logic designs
What is SN74HC139NS used for?
The SN74HC139NS is a standard component in microprocessor address decoding circuits where 2 select lines must activate one of 4 chip-enable signals for memory banks, peripheral registers, or I/O port expansion. It is also used in data demultiplexing stages on FPGA development boards and digital control panels to route control signals to one of 4 target subsystems based on a 2-bit address.
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
Where can I find the SN74HC139NS datasheet?
SN74HC139NS Datasheet DownloadOfficial datasheet from Texas Instruments
What are equivalent replacements for SN74HC139NS?
Compatible alternatives and drop-in replacements for SN74HC139NS:
Frequently Asked Questions
How does the enable pin on each section of the SN74HC139NS affect bus expansion designs?
Each of the 2 decoder sections in the SN74HC139NS has its own active-low enable input, so both halves can be independently gated off by asserting their respective enable high. This allows a single IC to act as an 8-output decoder when the enable of section B is driven by one of the active-low outputs of section A, cascading the two 2-to-4 decoders into a 3-to-8 configuration.
Over what supply voltage range does the SN74HC139NS operate and how does voltage affect speed?
The SN74HC139NS operates from 2 V to 6 V. At 2 V supply the propagation delay is approximately 27 ns, at 4.5 V it drops to roughly 8 ns, and at 6 V it falls below 7 ns. Designers targeting 50 MHz address decode cycles should use the 5 V or higher supply to ensure the 7 ns delay meets setup-time budgets for fast SRAM and CPLD chip-select inputs.
Can the SN74HC139NS decode a 3-bit address to 8 outputs using only a single IC?
Yes. By connecting address bit A2 to the enable of section B and its complement (or one of section A's 4 active-low outputs) to the enable of section A, both 2-to-4 sections together respond to a full 3-bit address, producing 8 mutually exclusive active-low chip-select outputs from 3 address lines and 1 chip within a 16-pin SOP package.
What output drive strength does the SN74HC139NS provide and what bus loads can it handle?
The SN74HC139NS HC CMOS outputs source and sink approximately 4 mA at 5 V supply into standard logic loads, sufficient to drive 10 or more LS-TTL inputs or a series of HC CMOS chip-enable pins with fanout up to 50 unit loads. Pull-up resistors of 4.7 kΩ or lower are recommended if the outputs must drive 3.3 V inputs from a 5 V supply rail.
Related Guides
CSD87313DMS Synchronous Buck Power Stage Design Guide
Design a compact CSD87313DMS synchronous buck stage with practical guidance for loss, gate drive, PCB layout, EMI, thermal validation, and sourcing.
Aug 6, 2026
STEF05SGR eFuse Selection Guide for 5 V Overcurrent Protection
Choose STEF05SGR for 5 V overcurrent protection by checking current-limit margin, inrush, thermal loss, fault response, and sourcing.
Aug 6, 2026
C0402C103K3RACTU Selection Guide: Choosing a 10 nF 0402 MLCC
Select C0402C103K3RACTU by voltage margin, X7R behavior, tolerance, 0402 assembly risk, and qualified alternatives.
Aug 4, 2026
STM32H753VIT6 MCU Selection Guide: Memory, Package, Connectivity, and Security
Choose STM32H753VIT6 by evaluating memory architecture, LQFP-100 pin fit, connectivity, security, power, and sourcing tradeoffs.
Aug 4, 2026
Why Buy from FindMyChip
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.
More from Texas Instruments
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“Their engineering team helped us find a pin-compatible alternative when our original MCU went EOL.”
You May Also Like
ACS770ECB-200U-PFF-T
Allegro Microsystems
Integrated Circuit
ACS770KCB-150U-PFF-T
Allegro Microsystems
Integrated Circuit
MC33901WEF
NXP
Integrated Circuit
MC7808BDTRKG
ON Semiconductor
Integrated Circuit
PA94EC
Apex Microtechnology
Integrated Circuit
AP7315-28SR-7
Diodes Inc.
Integrated Circuit
74HCT245D
Nexperia
Integrated Circuit
CY62256VNLL-70ZXCT
Cypress Semiconductor
Integrated Circuit
EPM7032AETC44-4N
Intel
Integrated Circuit
EPM3512AQC208-10N
Intel
Integrated Circuit
EPM3256ATC144-7N
Intel
Integrated Circuit
EPM3256AQC208-7N
Intel
Integrated Circuit
EPM3256AQC208-10N
Intel
Integrated Circuit
EPM3128ATC100-7N
Intel
Integrated Circuit
EPM1270F256C4N
Intel
Integrated Circuit
EPF8282ATC100-4N
Intel
Integrated Circuit
EPF6016QC208-2N
Intel
Integrated Circuit
EPF6016ATC144-3N
Intel
Integrated Circuit
EPF10K30ATC144-3N
Intel
Integrated Circuit
EPC2TI32N
Intel
Integrated Circuit
EPC2LC20
Intel
Integrated Circuit
EP3SL150F1152C4N
Intel
Integrated Circuit
EP2SGX60DF780C5N
Intel
Integrated Circuit
EP2SGX60CF780C5N
Intel
Integrated Circuit