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Texas Instruments SN74AHC139D
- Part No.:
- SN74AHC139D
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74AHC139D.pdf
- Description:
- IC DECODER/DEMUX 1X2:4 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,480
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Product details
Overview
SN74AHC139D from Texas Instruments is a dual 2-line-to-4-line decoder/demultiplexer IC designed for high-speed memory decoding and data-routing applications. It operates across 2V–5.5V VCC, delivers propagation delays as low as 5 ns (at 5 V, 15 pF), features active-low enable inputs per channel, and provides CMOS-compatible balanced outputs with ±8 mA drive capability at 5 V.
For engineers reviewing the SN74AHC139D datasheet, SN74AHC139D pinout, SN74AHC139D application, or SN74AHC139D equivalent, key selection considerations include its dual-channel independent enable control, 16-pin SOIC (D) package compatibility, low-power AHC logic family performance, and suitability for chip-select generation in multi-device memory or peripheral bus systems.
Technical Context
The SN74AHC139D implements two independent 2:4 decoders with positive-logic address decoding and active-low output enables (1G, 2G). Each channel decodes binary inputs A1/A0 to assert exactly one of four active-low outputs (Y0–Y3), while unselected outputs remain high-impedance when enabled or forced high when disabled.
Its AHC-family silicon-gate CMOS architecture ensures rail-to-rail output swing, low static current (≤40 µA), and robust ESD protection (±2000 V HBM, ±1000 V CDM), enabling reliable operation in noise-sensitive digital systems without external level-shifting or buffering.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2 V to 5.5 V - supports direct interface with 3.3 V and 5 V logic families without level translation |
| tPHL/tPLH (5 V, 15 pF) | 5 ns typical - enables sub-10 ns system-level address decode latency in memory subsystems |
| IOH/IOL (5 V) | ±8 mA - drives standard TTL loads or multiple CMOS inputs without external buffers |
| Input Thresholds (5.5 V) | VIL = 1.65 V max, VIH = 3.85 V min - ensures noise margins >0.7 V under worst-case supply and temperature |
| Ci (5 V) | 10 pF max - minimizes capacitive loading on upstream drivers and simplifies PCB routing |
| PDP (5 V, 1 MHz) | 13 pF typical - enables ultra-low dynamic power consumption in battery-powered or thermally constrained designs |
Pinout & Package
SN74AHC139D is supplied in a 16-pin SOIC (Small Outline Integrated Circuit) package measuring 9.90 mm × 6.00 mm, with 1.27 mm lead pitch and gull-wing surface-mount terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 15 | 1G, 2G | Active-low enable inputs - disable entire channel output when high; essential for cascading or bus arbitration |
| 2, 3, 13, 14 | 1A0, 1A1, 2A0, 2A1 | Binary address select inputs - determine which of four outputs (Y0–Y3) is asserted per channel |
| 4–7, 9–12 | 1Y0–1Y3, 2Y0–2Y3 | Active-low decoded outputs - sink current when selected; remain high-impedance when disabled |
| 8 | GND | Ground reference - must be low-impedance connection to minimize switching noise coupling |
| 16 | VCC | Positive supply - requires local 0.1 µF ceramic bypass capacitor placed adjacent to pin |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 2:4 decode channels | Enables simultaneous control of two separate 4-device groups (e.g., memory banks or peripherals) with no shared timing constraints |
| Active-low per-channel enable (G) | Allows hierarchical decoding - e.g., one SN74AHC139D selects between two banks, each controlled by another SN74AHC139D |
| CMOS balanced outputs (±8 mA @ 5 V) | Drives up to 10 LSTTL loads or 20+ CMOS inputs directly, eliminating need for buffer stages in most embedded systems |
| Low input capacitance (10 pF max) | Reduces loading on microcontroller GPIO pins, preserving signal integrity and timing margins in high-speed address buses |
| Latch-up immunity >250 mA | Ensures robustness against transient overvoltage events in industrial or automotive environments without external protection |
Applications
| Memory Address Decoding | Peripheral Device Selection |
|---|---|
Use Scenario: Selecting one of four SRAM/Flash chips sharing a common data/address bus in a microcontroller-based data logger. IC Role / Device Role / Timing Role: Generates chip-select (CS) signals synchronized to address bus transitions, with propagation delay <8.5 ns ensuring no bus contention. Use Value: Eliminates need for discrete logic or FPGA resources; reduces BOM count and PCB area versus discrete gate solutions. | Use Scenario: Enabling specific sensor modules (I²C or SPI) on a shared bus in an industrial IoT gateway. IC Role / Device Role / Timing Role: Acts as a hardware-mapped device selector, isolating communication paths to prevent protocol collisions during concurrent sensor reads. Use Value: Provides deterministic, zero-software-latency device activation - critical for time-triggered sensor polling sequences. |
| Bus Expansion Interface | Logic State Multiplexing |
Use Scenario: Expanding limited GPIO count of an ARM Cortex-M0+ MCU to control eight discrete actuators via two SN74AHC139D devices. IC Role / Device Role / Timing Role: Translates 4-bit encoded control word into individual actuator enable lines, with dual-channel structure supporting parallel activation groups. Use Value: Achieves 1:4 fan-out per device using only two address lines and one enable - 75% fewer GPIOs than direct control. | Use Scenario: Routing a single digital control signal (e.g., reset, interrupt) to one of four functional blocks in an FPGA configuration manager. IC Role / Device Role / Timing Role: Functions as a demultiplexer where strobe (G) serves as data input and A1/A0 select destination block. Use Value: Enables precise, glitch-free signal routing without clock domain crossing or metastability concerns inherent in register-based muxes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar decoder/demultiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HC139DR | Slower propagation delay (15 ns typical at 5 V), higher ICC (80 µA max), same pinout and logic function | Acceptable where system timing budget allows ≥15 ns decode latency; lower cost in high-volume production | Choose for cost-sensitive, non-high-speed applications where AHC speed is unnecessary |
| 74LVC139AD | Wider VCC range (1.65–5.5 V), lower tPLH (3.8 ns typ at 3.3 V), but reduced latch-up immunity (100 mA) | Better suited for mixed-voltage 1.8 V/3.3 V systems; requires stricter ESD handling in harsh environments | Prefer for portable or low-voltage designs needing faster 3.3 V performance and broader supply flexibility |
Compared with SN74HC139DR and 74LVC139AD, the SN74AHC139D delivers optimal balance of speed (5 ns), power efficiency (40 µA ICC), and ruggedness (250 mA latch-up) for industrial memory and bus-control applications operating at 3.3 V or 5 V.
Availability
SN74AHC139D is available at Aetrix Electronics and suitable for memory address decoding, peripheral selection, bus expansion, and logic state multiplexing requiring stable component supply, long-term lifecycle support, and consistent parametric performance across temperature extremes.
Supply support for SN74AHC139D includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader delivering analog and embedded processing solutions, with over 90 years of innovation in logic, power, and signal-chain technologies.
The SN74AHC139D belongs to TI's advanced high-speed CMOS (AHC) logic family, engineered specifically for low-power, high-speed memory decoding and data-routing systems where minimal propagation delay and rail-to-rail output swing are critical.
FAQ
What is the maximum operating temperature range for the SN74AHC139D?
The SN74AHC139D is rated for operation from –40°C to +125°C ambient temperature. This extended industrial temperature range ensures reliable functionality in demanding environments such as factory automation controllers, automotive body electronics, and outdoor communications equipment where thermal cycling and sustained high-temperature operation occur.
Does the SN74AHC139D support 3.3 V-only operation?
Yes, the SN74AHC139D fully supports 3.3 V operation with guaranteed performance: propagation delay ≤11 ns (at 3.3 V, 15 pF), output drive ±4 mA, and input thresholds compatible with 3.3 V CMOS logic levels. Its 2 V–5.5 V VCC range makes it ideal for mixed-voltage systems without level shifters.
How does the enable input (G) function in the SN74AHC139D?
In the SN74AHC139D, each channel has its own active-low enable input (1G or 2G). When G is high, all four outputs (Y0–Y3) for that channel are forced high-impedance regardless of address inputs. When G is low, the decoder operates normally - asserting exactly one low output based on A1/A0. This enables cascading and bus isolation.
Can unused inputs on the SN74AHC139D be left floating?
No - unused inputs on the SN74AHC139D must never be left floating. Standard CMOS inputs require termination to VCC or GND to prevent undefined logic states, excessive power consumption, or oscillation. TI recommends using 10 kΩ pull-up or pull-down resistors for unused address or enable inputs to ensure stable operation across temperature and voltage ranges.
What is the recommended bypass capacitor for the SN74AHC139D?
Texas Instruments specifies a 0.1 µF ceramic capacitor placed as close as possible to the VCC and GND pins of the SN74AHC139D. This minimizes high-frequency supply noise and prevents voltage droop during output switching transients. For enhanced noise rejection, a parallel 1 µF capacitor may be added, but the 0.1 µF unit remains mandatory for stable high-speed operation.
SN74AHC139D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AHC
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Type:
- Decoder/Demultiplexer
- Circuit:
- 1 x 2:4
- Independent Circuits:
- 2
- Current - Output High, Low:
- 8mA, 8mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 2V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
SN74AHC139D FAQ
1.How can I place an order for SN74AHC139D through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AHC139D on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SN74AHC139D reliable?
The price and inventory of SN74AHC139D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AHC139D is usually 5 days.
3.What payment methods are accepted for SN74AHC139D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74AHC139D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74AHC139D?
SN74AHC139D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AHC139D order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SN74AHC139D?
For technical support, including SN74AHC139D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AHC139D requirements.
6.How does Aetrix verify that SN74AHC139D is sourced from the original manufacturer or authorized distributors?
All SN74AHC139D products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SN74AHC139D meets industry standards.
7.What is the process for return or replacement of SN74AHC139D?
All SN74AHC139D units undergo pre-shipment inspection (PSI). If there is an issue with SN74AHC139D, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SN74AHC139D part is unused and in its original packaging.
Return procedure for SN74AHC139D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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