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Texas Instruments CD74HC139MT
- Part No.:
- CD74HC139MT
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
CD74HC139MT.pdf
- Description:
- IC DECODER/DEMUX 1X2:4 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,296
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Product details
Overview
CD74HC139MT from Texas Instruments is a dual 2-to-4 line decoder/demultiplexer in SOIC-16 package, operating from 2V to 6V with -55°C to +125°C temperature range. It features active-low mutually exclusive outputs, 10 LSTTL load fanout, and propagation delays as low as 25 ns at 6V. It serves in memory decoding, data routing, and code conversion circuits where precise binary selection and low-power CMOS logic are required.
For engineers reviewing the CD74HC139MT datasheet, CD74HC139MT pinout, CD74HC139MT application, or CD74HC139MT equivalent, key selection criteria include supply voltage compatibility (2–6V), output drive capability (10 LSTTL loads), propagation delay (25–220 ns depending on VCC), wide temperature operation (-55°C to +125°C), and dual independent decoder functionality with active-low enable control.
Technical Context
The CD74HC139MT integrates two identical binary-to-1-of-4 decoders, each with separate active-low enable (1E/2E) and dual select inputs (A0/A1). Each decoder drives four active-low outputs (Y0–Y3), ensuring only one output is low per valid input combination when enabled.
It implements standard HC CMOS logic with balanced propagation delay and transition times, high noise immunity (NIL/NIH = 30% of VCC at 5V), and quiescent current as low as 8 µA at 25°C. Outputs remain high when enable is high, supporting cascading via enable-as-chip-select functionality.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2V to 6V - supports single-supply operation across industrial and extended-temperature systems without level-shifting. |
| Propagation Delay (A0/A1 → Y) | 25 ns max at 6V, CL = 50 pF - enables reliable timing in high-speed address decoding up to ~20 MHz. |
| Output Drive Capability | 10 LSTTL loads - sufficient to directly interface with legacy TTL logic without buffers in mixed-logic systems. |
| Operating Temperature | -55°C to +125°C - qualified for aerospace, military, and harsh-environment industrial applications. |
| Input Leakage Current | ±1 µA max at 6V - ensures minimal power loss and stable logic levels in battery-powered or high-impedance nodes. |
| Power Dissipation Capacitance | 55 pF - allows accurate dynamic power estimation using PD = VCC² × fi × (CPD + CL). |
| Logic Family | High-Speed CMOS (HC) - provides LSTTL-compatible speed with CMOS power efficiency and noise immunity. |
Pinout & Package
CD74HC139MT is housed in a 16-pin Small Outline Integrated Circuit (SOIC) package with standard 1.27 mm pitch, JEDEC MS-012AC compliant, moisture sensitivity level 1 (260°C reflow compatible).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1E, 2E | Active-low enable inputs | Enable/disable respective decoder; high = all outputs forced high; used for chip select in cascaded configurations. |
| 1A0, 1A1 / 2A0, 2A1 | Binary select inputs | Two-bit address inputs per decoder; determine which of four outputs goes low (active-low decode). |
| 1Y0–1Y3 / 2Y0–2Y3 | Active-low decoded outputs | Four mutually exclusive low-active outputs per decoder; support demultiplexing when enable is used as data input. |
| VCC | Positive supply | CMOS supply rail (2–6V); must be decoupled locally to suppress switching noise. |
| GND | Ground reference | Common return path for all inputs, outputs, and internal logic; critical for noise immunity and signal integrity. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent decoders | Enables two parallel 2-to-4 decode paths on one IC-reduces board space and BOM count versus discrete solutions. |
| Active-low mutually exclusive outputs | Guarantees only one output is asserted low per valid input, eliminating bus contention in address decoding and peripheral selection. |
| Wide supply voltage range (2–6V) | Permits direct interfacing with 3.3V microcontrollers, 5V legacy systems, and low-voltage battery-powered designs without level shifters. |
| High noise immunity (30% VCC) | Ensures robust operation in electrically noisy environments such as motor control or industrial PLC backplanes. |
| Low quiescent current (8 µA typ) | Supports ultra-low-power standby modes in portable instrumentation and remote sensor nodes. |
Applications
| Memory Address Decoding | Data Routing in Industrial PLCs |
|---|---|
Use Scenario: Selecting one of four RAM or ROM chips in a microcontroller-based embedded system with limited address lines. IC Role / Device Role / Timing Role: Dual decoder maps 2-bit address segments to individual chip-enable signals; propagation delay ≤25 ns ensures setup/hold compliance at 20 MHz bus clocks. Use Value: Eliminates need for discrete logic gates or larger CPLDs, reducing component count and PCB area while maintaining deterministic timing. | Use Scenario: Distributing serial command data from a central controller to four independent I/O modules in an industrial automation rack. IC Role / Device Role / Timing Role: Functions as demultiplexer: enable pin accepts serial data stream; A0/A1 selects destination module; outputs drive opto-isolator inputs. Use Value: Provides galvanically isolated, noise-immune data distribution with no external buffering-critical for EMI-prone factory floor environments. |
| Code Conversion for Display Drivers | Priority Encoder Support Logic |
Use Scenario: Converting 2-bit binary inputs into segment-enable signals for a 4-digit multiplexed LED display with common-anode configuration. IC Role / Device Role / Timing Role: Decoder outputs drive digit-select lines; active-low outputs match common-anode LED polarity; fanout of 10 LSTTL loads directly drives LED column drivers. Use Value: Simplifies display interface design by removing external inverters and current-limiting resistor networks per digit. | Use Scenario: Generating mask signals for a priority encoder that resolves interrupt requests from four peripheral devices. IC Role / Device Role / Timing Role: Each decoder output enables one encoder channel; enable pins synchronize decoding with interrupt acknowledge cycles. Use Value: Enables deterministic interrupt prioritization with sub-30 ns latency-essential for real-time response in safety-critical control loops. |
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 |
|---|---|---|---|
| CD74HCT139MT | LSTTL-input compatible (VIH ≥ 2V, VIL ≤ 0.8V); operates only at 4.5–5.5V. | Better suited for 5V-only systems interfacing with legacy TTL or microcontrollers lacking CMOS-level outputs. | Select when interfacing with 5V LSTTL sources; avoid if supply varies below 4.5V or exceeds 5.5V. |
| SN74HC139DR | Same HC logic family and pinout; TI's newer SOIC-16 packaging with enhanced thermal performance (θJA = 70°C/W vs. 73°C/W). | Identical functional behavior but optimized for higher-density PCB layouts and improved thermal reliability in compact enclosures. | Prefer for new designs requiring tighter thermal margins or alignment with TI's current production roadmap. |
Compared with CD74HC139MT, CD74HCT139MT offers stricter 5V TTL compatibility at the cost of supply flexibility, while SN74HC139DR delivers identical logic performance with marginally better thermal characteristics-making it suitable for thermally constrained applications without changing circuit design.
Availability
CD74HC139MT is available at Aetrix Electronics and suitable for memory decoding, industrial data routing, and code conversion applications requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for CD74HC139MT 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 specializing in analog, embedded processing, and logic solutions, with decades of heritage in high-reliability logic families.
The CD74HC139MT belongs to TI's High-Speed CMOS (HC) logic portfolio, designed for low-power, wide-voltage-range digital interfacing in aerospace, defense, and industrial systems demanding extended temperature operation and long-term supply stability.
FAQ
What is the maximum clock frequency supported by CD74HC139MT in decoder mode?
The CD74HC139MT does not operate on a clock; it is combinational logic. Its usable input toggle rate depends on propagation delay and system timing margins. At 6V and CL = 50 pF, tPLH/tPHL is 25 ns max, supporting reliable operation up to approximately 20 MHz for address/data transitions with adequate setup/hold time.
Can CD74HC139MT drive LEDs directly without current-limiting resistors?
No. While CD74HC139MT outputs can sink up to 25 mA per pin, driving LEDs directly risks exceeding absolute maximum ratings and damaging the device. External current-limiting resistors are mandatory to constrain output current within safe operating limits and ensure consistent LED brightness.
Is CD74HC139MT pin-compatible with CD4556B?
Yes. The CD74HC139MT is explicitly stated in its datasheet to be functionally identical and pin-compatible with the CD4556B, enabling drop-in replacement in existing designs using that older CMOS decoder, provided voltage and timing requirements are verified.
Does CD74HC139MT support mixed-voltage operation between inputs and outputs?
No. CD74HC139MT is a single-supply device: all inputs and outputs reference the same VCC rail. Input high/low thresholds scale with VCC (e.g., VIH = 1.5V min at 2V, 4.2V min at 6V), so interfacing with different voltage domains requires level-shifting circuitry.
What is the meaning of the 'T' suffix in CD74HC139MT?
The 'T' suffix in CD74HC139MT indicates a small-quantity tape-and-reel packaging option containing 250 units per reel, intended for prototyping, evaluation, and low-volume production-distinct from the 'M96' variant which contains 2500 units per reel.
CD74HC139MT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HC
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Decoder/Demultiplexer
- Circuit:
- 1 x 2:4
- Independent Circuits:
- 2
- Current - Output High, Low:
- 5.2mA, 5.2mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 2V ~ 6V
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
CD74HC139MT FAQ
1.How can I place an order for CD74HC139MT through Aetrix?
Please submit a Request for Quotation (RFQ) for CD74HC139MT 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 CD74HC139MT reliable?
The price and inventory of CD74HC139MT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CD74HC139MT is usually 5 days.
3.What payment methods are accepted for CD74HC139MT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CD74HC139MT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CD74HC139MT?
CD74HC139MT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CD74HC139MT 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 CD74HC139MT?
For technical support, including CD74HC139MT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CD74HC139MT requirements.
6.How does Aetrix verify that CD74HC139MT is sourced from the original manufacturer or authorized distributors?
All CD74HC139MT 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 CD74HC139MT meets industry standards.
7.What is the process for return or replacement of CD74HC139MT?
All CD74HC139MT units undergo pre-shipment inspection (PSI). If there is an issue with CD74HC139MT, 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 CD74HC139MT part is unused and in its original packaging.
Return procedure for CD74HC139MT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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