My Inquiry
My Account
Texas Instruments CD74HCT139EG4
- Part No.:
- CD74HCT139EG4
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
CD74HCT139EG4.pdf
- Description:
- IC DECODER/DEMUX 1X2:4 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,176
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
CD74HCT139EG4 from Texas Instruments is a dual 2-to-4 line decoder/demultiplexer IC with active-low enable and mutually exclusive active-low outputs. It operates from 4.5 V to 5.5 V, supports LSTTL-compatible inputs (VIL ≤ 0.8 V, VIH ≥ 2.0 V), delivers ±25 mA output drive, and functions across –55 °C to +125 °C for industrial and military-grade systems including memory address decoding and data routing.
For engineers reviewing the CD74HCT139EG4 datasheet, CD74HCT139EG4 pinout, CD74HCT139EG4 application, or CD74HCT139EG4 equivalent, key selection criteria include its HCT-family logic compatibility, dual-decoder architecture with independent enables, propagation delay of 34 ns (max) at 5 V, fanout of 10 LSTTL loads, and PDIP-16 package suitability for through-hole prototyping and legacy board designs.
Technical Context
The CD74HCT139EG4 integrates two independent binary-to-1-of-4 decoders, each with a dedicated active-low enable input (1E, 2E) and select inputs (A0, A1). Each decoder drives four active-low outputs (Y0–Y3), where only one output goes low per valid input combination; all outputs remain high when the enable is asserted high.
It implements standard CMOS logic with TTL-compatible input thresholds and rail-to-rail output swing. Its internal structure supports demultiplexer operation (with enable as data input) and cascading via enable chaining, and it is functionally identical-and pin compatible-with the CD4556B.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | HCT - TTL-compatible inputs, CMOS power efficiency, 4.5–5.5 V supply |
| Function | Dual 2-to-4 decoder / 1-to-4 demultiplexer with independent enables |
| Propagation Delay | 34 ns max (A0/A1 to Y, E to Y, CL = 50 pF, VCC = 4.5 V) |
| Output Drive | ±25 mA per output - sufficient to directly drive LSTTL loads without buffers |
| Operating Temperature | –55 °C to +125 °C - qualified for extended industrial and military environments |
| Fanout | 10 LSTTL loads - ensures signal integrity across multiple downstream gates |
| Input Thresholds | VIL ≤ 0.8 V (max), VIH ≥ 2.0 V (min) - guarantees reliable interfacing with 5 V TTL logic |
Pinout & Package
CD74HCT139EG4 is supplied in a 16-pin plastic dual in-line package (PDIP), with 0.3-inch body width and through-hole mounting. Pin spacing follows JEDEC MS-001 standard.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1E, 2E | Active-low enable inputs | Enable respective decoder; high = all outputs forced high (disabled) |
| 1A0, 1A1 / 2A0, 2A1 | Binary select inputs | Address bits selecting one of four active-low outputs per decoder |
| 1Y0–1Y3 / 2Y0–2Y3 | Active-low decoded outputs | Only one output per decoder goes low per valid input; mutually exclusive |
| VCC (Pin 16) | Positive supply | 4.5–5.5 V DC; powers both decoder sections |
| GND (Pin 8) | Ground reference | Common return path for all logic and output currents |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent decoders | Enables compact implementation of two separate 2-to-4 decode paths on one IC |
| Active-low mutually exclusive outputs | Reduces external OR/NOR logic needed for priority encoding or bus arbitration |
| LSTTL input compatibility | Eliminates level-shifting circuitry when interfacing with legacy 5 V TTL systems |
| Wide temperature range support | Validated operation from –55 °C to +125 °C meets MIL-PRF-38535 Class B requirements |
| Pin compatibility with CD4556B | Allows drop-in replacement in existing designs using that legacy CMOS decoder |
Applications
| Memory Address Decoding | Data Routing |
|---|---|
Use Scenario: Selecting one of four memory banks or peripheral devices using two address lines and an enable signal. IC Role / Device Role / Timing Role: Decoder translating A0/A1 and chip-select into individual active-low device selects. Use Value: Reduces PCB trace count vs. discrete gate solutions and eliminates timing skew between parallel decode paths. | Use Scenario: Directing a single data stream to one of four destinations based on control bits. IC Role / Device Role / Timing Role: Demultiplexer with enable-as-data input; routes serial or parallel data under address control. Use Value: Provides deterministic, glitch-free channel selection without added latching or clock domain crossing. |
| Code Conversion | Industrial Control Logic |
Use Scenario: Converting 2-bit binary commands into four distinct actuator enable signals (e.g., motor phases, valve drivers). IC Role / Device Role / Timing Role: Binary-to-one-hot translator driving discrete power stages or relay drivers. Use Value: Ensures only one output is active at a time, preventing shoot-through or conflicting control states. | Use Scenario: Implementing state-dependent I/O expansion in programmable logic controllers with thermal-hardened operation. IC Role / Device Role / Timing Role: Local decode engine for modular I/O backplanes operating in harsh ambient conditions. Use Value: Maintains functional reliability across –55 °C to +125 °C without derating or external thermal management. |
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 |
|---|---|---|---|
| CD74HC139E | HC family: 2–6 V supply, higher noise immunity, but not LSTTL-input compatible | Requires level-shifting when interfacing with 5 V TTL; unsuitable for direct LS replacement | Select when wider supply range or lower static current (<1 µA) is prioritized over TTL compatibility |
| SN74LS139N | LS-TTL family: 4.75–5.25 V only, higher ICC, no CMOS power advantage | Higher power draw (≈20 mA typical), limited temp range (0–70 °C), not drop-in for extended temp designs | Choose only for legacy LS-only systems where HCT's power savings and temp range are unnecessary |
Compared with CD74HC139E and SN74LS139N, CD74HCT139EG4 uniquely balances TTL-level input compatibility, wide temperature operation, and CMOS efficiency-making it optimal for upgrading legacy LS designs while retaining pinout and signal integrity.
Availability
CD74HCT139EG4 is available at Aetrix Electronics and suitable for memory decoding, data routing, code conversion, and industrial control applications requiring stable component supply across extended temperature ranges.
Supply support for CD74HCT139EG4 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, embedded processing, and logic solutions for industrial, automotive, and communications markets.
The CD74HCT139EG4 belongs to TI's High-Speed CMOS Logic (HCT) family, engineered to replace bipolar TTL with CMOS efficiency while maintaining full input/output compatibility for seamless system upgrades.
FAQ
What is the supply voltage range supported by CD74HCT139EG4?
The CD74HCT139EG4 operates strictly within 4.5 V to 5.5 V. Unlike HC variants, it does not support 2 V or 6 V rails. This narrow range ensures precise TTL-compatible input thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V) and robust noise immunity at 5 V nominal systems. Operation outside this window may cause undefined logic states or damage. Always verify VCC stability within ±5% during design validation for CD74HCT139EG4.
Is CD74HCT139EG4 pin compatible with CD4556B?
Yes, CD74HCT139EG4 is explicitly documented as pin compatible with CD4556B. Both share identical 16-pin PDIP layout, terminal assignments (including VCC, GND, dual enables, dual select pairs, and eight active-low outputs), and functional truth tables. This allows direct substitution in legacy CMOS designs without PCB modification, provided the 4.5–5.5 V supply constraint of CD74HCT139EG4 is met.
What is the maximum output current per pin for CD74HCT139EG4?
The CD74HCT139EG4 supports ±25 mA DC output current per pin - meaning each Y0–Y3 output can sink or source up to 25 mA continuously. This rating enables direct drive of LSTTL loads (10-unit fanout) and small LEDs or relay drivers without external buffers. Exceeding this limit risks parametric shift or long-term reliability degradation in CD74HCT139EG4.
Does CD74HCT139EG4 support demultiplexer functionality?
Yes, CD74HCT139EG4 supports demultiplexer operation: the active-low enable input (1E or 2E) serves as the data input, while A0/A1 select the output channel. When enabled, the data appears inverted on the selected Yx output; all other outputs remain high. This mode is confirmed in the functional description and truth table of the CD74HCT139EG4 datasheet and requires no external components.
What is the operating temperature range of CD74HCT139EG4?
The CD74HCT139EG4 is rated for –55 °C to +125 °C, validated across the full range per MIL-PRF-38535 requirements. This extended specification supports deployment in aerospace, downhole, and industrial control environments where ambient extremes exceed commercial-grade limits. Derating is not required, and all electrical parameters-including propagation delay and output drive-are guaranteed across this span for CD74HCT139EG4.
CD74HCT139EG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HCT
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- 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
CD74HCT139EG4 FAQ
1.How can I place an order for CD74HCT139EG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for CD74HCT139EG4 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 CD74HCT139EG4 reliable?
The price and inventory of CD74HCT139EG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CD74HCT139EG4 is usually 5 days.
3.What payment methods are accepted for CD74HCT139EG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CD74HCT139EG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CD74HCT139EG4?
CD74HCT139EG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CD74HCT139EG4 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 CD74HCT139EG4?
For technical support, including CD74HCT139EG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CD74HCT139EG4 requirements.
6.How does Aetrix verify that CD74HCT139EG4 is sourced from the original manufacturer or authorized distributors?
All CD74HCT139EG4 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 CD74HCT139EG4 meets industry standards.
7.What is the process for return or replacement of CD74HCT139EG4?
All CD74HCT139EG4 units undergo pre-shipment inspection (PSI). If there is an issue with CD74HCT139EG4, 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 CD74HCT139EG4 part is unused and in its original packaging.
Return procedure for CD74HCT139EG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
CD74HCT139EG4 Tags
-
SN74HC138DR
Texas Instruments
-
TC7SB3157CFU,LF(CT
Toshiba Semiconductor and Storage
-
74CBTLV3257PW,118
Nexperia USA Inc.
-
SN74CBTLV3257PWR
Texas Instruments
-
74CBTLV3257GUX
Nexperia USA Inc.
-
74HC154BQ,118
Nexperia USA Inc.
-
P3S0200GMX
NXP USA Inc.
-
SN74CB3Q3245PWR
Texas Instruments
-
SN74CB3Q3257RGYR
Texas Instruments
-
TCA9543APWR
Texas Instruments
-
TCA9546APWR
Texas Instruments
-
SN74HC138N
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
