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Texas Instruments CD74HCT139EE4
- Part No.:
- CD74HCT139EE4
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
CD74HCT139EE4.pdf
- Description:
- HIGH SPEED CMOS LOGIC DUAL 2-TO-
- Quantity:
- Payment:
- Shipping:
Inventory:2,984
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Product details
Overview
CD74HCT139EE4 from Texas Instruments is a dual 2-to-4 line decoder/demultiplexer IC with active-low enable and mutually exclusive active-low outputs, operating at 4.5V–5.5V, supporting LSTTL-compatible inputs (VIL ≤ 0.8V, VIH ≥ 2V), and rated for -55°C to +125°C industrial/military temperature range.
For engineers reviewing the CD74HCT139EE4 datasheet, CD74HCT139EE4 pinout, CD74HCT139EE4 application, or CD74HCT139EE4 equivalent, key selection factors include its dual-decoder architecture, TTL-input compatibility, wide temperature operation, low-power CMOS design, and PDIP-16 package suitability for legacy board designs and prototyping.
Technical Context
The CD74HCT139EE4 integrates two independent binary-to-1-of-4 decoders, each with one active-low enable input (1E/2E) and two select inputs (A0/A1); data on A0/A1 selects exactly one of four active-low outputs (Y0–Y3) when the corresponding enable is low.
It functions as a demultiplexer when the enable input serves as the data path, and supports cascading via enable chaining for larger decoding trees; output drive capability is 10 LSTTL loads, with propagation delays of 34–51 ns (A0/A1 or E to Y, CL = 50 pF, VCC = 4.5 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | HCT - TTL-compatible input thresholds (VIH ≥ 2V, VIL ≤ 0.8V) ensure direct replacement of LS TTL in 5V systems |
| Supply Voltage Range | 4.5V to 5.5V - guarantees stable operation across standard 5V ±5% rails without level-shifting |
| Operating Temperature | -55°C to +125°C - qualified for extended industrial, automotive under-hood, and military applications |
| Propagation Delay | 34 ns (typ), 51 ns (max) - enables reliable timing in synchronous logic up to ~10 MHz clock domains |
| Output Drive | 10 LSTTL loads - sufficient to directly drive multiple 74LS inputs without buffering |
| Input Leakage | ≤ ±1 µA - minimizes static current draw and prevents unintended logic transitions in high-impedance nodes |
| Power Dissipation Cap. | 59 pF - used to calculate dynamic power: PD = VCC² × fi × (CPD + CL), critical for thermal budgeting |
Pinout & Package
CD74HCT139EE4 uses a 16-pin plastic dual in-line package (PDIP-N), with 0.3-inch body width and through-hole mounting. Pin 1 is located at the top-left corner (notch/left-index mark side), and the package is RoHS-compliant with NiPdAu lead finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1E, 2E | Active-low enable inputs | Enable/disable respective decoder; high = all outputs forced high (disabled state) |
| 1A0, 1A1 / 2A0, 2A1 | Binary select inputs | Two-bit address determining which of four outputs goes low (Y0–Y3 per decoder) |
| 1Y0–1Y3 / 2Y0–2Y3 | Active-low decoded outputs | Mutually exclusive low-state outputs; only one asserted per decoder at any time |
| VCC (Pin 16) | Positive supply | 4.5V–5.5V CMOS rail; must be decoupled locally to suppress switching noise |
| GND (Pin 8) | Ground reference | Common return for all inputs, outputs, and internal logic; requires low-impedance connection |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent decoders | Enables two separate 2-to-4 decode paths on one chip-reduces board space vs. discrete LS04+LS138 solutions |
| Active-low mutually exclusive outputs | Guarantees only one output low per decoder, eliminating bus contention in memory/data routing applications |
| LSTTL input compatibility | Accepts standard TTL voltage levels without external level shifters-direct drop-in replacement for 74LS139 in legacy 5V systems |
| Wide temperature range (-55°C to +125°C) | Validated for use in harsh environments including aerospace avionics, downhole tools, and engine control units |
| Low quiescent current (ICC ≤ 160 µA) | Reduces standby power in battery-backed or always-on subsystems compared to bipolar TTL equivalents |
Applications
| Memory Address Decoding | Data Routing in Bus Systems |
|---|---|
Use Scenario: Selecting one of four RAM/ROM chips in a microcontroller-based embedded system with limited address lines. IC Role / Device Role / Timing Role: CD74HCT139EE4 acts as a 2-bit address decoder, translating A0/A1 and chip-enable signals into individual chip-select lines. Use Value: Eliminates need for discrete NAND gates; ensures glitch-free, mutually exclusive chip selects due to synchronous enable-controlled output assertion. |
Use Scenario: Directing serial data from a UART or SPI controller to one of four peripheral devices (e.g., sensors, DACs) based on command byte. IC Role / Device Role / Timing Role: CD74HCT139EE4 functions as a demultiplexer, using the enable pin as the data input and A0/A1 as channel address bits. Use Value: Provides deterministic, low-latency channel selection (<51 ns max delay) with no external logic required-ideal for real-time I/O expansion. |
| Industrial Control Logic | Legacy System Modernization |
Use Scenario: Driving four independent relay drivers or opto-isolators in a programmable logic controller (PLC) I/O module. IC Role / Device Role / Timing Role: CD74HCT139EE4 provides isolated, current-limited enable signals to transistor driver stages, synchronized to PLC scan cycle. Use Value: Leverages 10-LSTTL load drive strength to directly interface with common base-drive circuits, reducing component count and failure points. |
Use Scenario: Replacing obsolete 74LS139 in aging test equipment or instrumentation where PCB layout cannot be modified. IC Role / Device Role / Timing Role: CD74HCT139EE4 serves as a pin- and function-compatible upgrade, maintaining identical PDIP-16 footprint and logic behavior. Use Value: Delivers identical pinout, truth table, and DC characteristics while cutting power consumption by >90% versus LS TTL-extending system lifetime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual 2-to-4 decoder/demultiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HCT139N | Same HCT logic family, identical pinout and electrical specs; TI's newer catalog version with updated packaging and RoHS compliance | No functional difference; optimized for new designs requiring current TI production support and full lifecycle documentation | Select SN74HCT139N for new designs requiring guaranteed long-term availability and TI's latest quality assurance protocols |
| 74AC139PC | AC-family device with wider VCC range (2V–6V), faster propagation (20 ns typ), but higher ICC and non-LSTTL-compatible inputs (VIH = 3.5V min @ 5V) | Requires input level adaptation in pure 5V TTL systems; unsuitable as direct LS139 replacement without redesign | Choose 74AC139PC only when higher speed and broader supply flexibility outweigh TTL compatibility requirements |
Compared with CD74HCT139EE4, SN74HCT139N offers identical functionality with enhanced manufacturing traceability and extended product longevity, while 74AC139PC trades TTL compatibility for speed and supply range-making CD74HCT139EE4 optimal for drop-in LS139 upgrades in temperature-critical legacy systems.
Availability
CD74HCT139EE4 is available at Aetrix Electronics and suitable for memory decoding, industrial control logic, data routing, and legacy system modernization requiring stable component supply across extended temperature ranges.
Supply support for CD74HCT139EE4 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 founded in 1930, specializing in analog, embedded processing, and logic ICs with broad industrial, automotive, and aerospace qualification.
The CD74HCT139EE4 belongs to TI's legacy High-Speed CMOS (HCT) logic family, designed specifically to provide TTL-compatible performance with CMOS power efficiency for robust 5V system upgrades and military-grade reliability.
FAQ
Is CD74HCT139EE4 pin-compatible with the original 74LS139?
Yes, CD74HCT139EE4 is pin-compatible and functionally equivalent to 74LS139, featuring identical PDIP-16 pinout, active-low outputs, and dual 2-to-4 decode architecture. Its LSTTL-compatible inputs (VIH ≥ 2V, VIL ≤ 0.8V) allow direct substitution without circuit modification in existing 5V designs.
What is the maximum clock/data rate supported by CD74HCT139EE4 in demultiplexer mode?
CD74HCT139EE4 supports data rates up to approximately 10 MHz in demultiplexer operation, based on its maximum propagation delay of 51 ns (E or A0/A1 to Y, CL = 50 pF, VCC = 4.5 V). For reliable setup/hold timing, input transitions should be limited to ≤10 MHz in synchronous systems.
Can CD74HCT139EE4 operate from a 3.3V supply?
No, CD74HCT139EE4 is specified only for 4.5V to 5.5V operation. At 3.3V, input thresholds (VIH ≥ 2V, VIL ≤ 0.8V) may not be reliably met, and output drive strength degrades significantly. Use CD74HC139E (2V–6V) or SN74LVC139A (1.65V–5.5V) for 3.3V systems.
Does CD74HCT139EE4 require external pull-up resistors on its outputs?
No, CD74HCT139EE4 has push-pull CMOS outputs and does not require external pull-ups. Its active-low outputs drive to near-GND (VOL ≤ 0.4V at 4 mA) when asserted and to near-VCC (VOH ≥ 3.7V at -4 mA) when inactive-fully compatible with TTL and CMOS inputs.
What is the thermal resistance (θJA) of the CD74HCT139EE4 PDIP package?
The CD74HCT139EE4 in PDIP (N) package has a typical junction-to-ambient thermal resistance (θJA) of 67°C/W, as specified in the datasheet. This value assumes standard JEDEC test conditions (single-layer board, 1 in² copper pad); actual θJA will vary with PCB layout and airflow.
CD74HCT139EE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HCT
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Decoder/Demultiplexer
- Circuit:
- 1 x 2:4
- Independent Circuits:
- 2
- Current - Output High, Low:
- 4mA, 4mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 16-PDIP
CD74HCT139EE4 FAQ
1.How can I place an order for CD74HCT139EE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for CD74HCT139EE4 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 CD74HCT139EE4 reliable?
The price and inventory of CD74HCT139EE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CD74HCT139EE4 is usually 5 days.
3.What payment methods are accepted for CD74HCT139EE4?
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4.How is shipping managed for CD74HCT139EE4?
CD74HCT139EE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CD74HCT139EE4 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 CD74HCT139EE4?
For technical support, including CD74HCT139EE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CD74HCT139EE4 requirements.
6.How does Aetrix verify that CD74HCT139EE4 is sourced from the original manufacturer or authorized distributors?
All CD74HCT139EE4 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 CD74HCT139EE4 meets industry standards.
7.What is the process for return or replacement of CD74HCT139EE4?
All CD74HCT139EE4 units undergo pre-shipment inspection (PSI). If there is an issue with CD74HCT139EE4, 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 CD74HCT139EE4 part is unused and in its original packaging.
Return procedure for CD74HCT139EE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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