My Inquiry
My Account
STMicroelectronics 74LCX139MTR
- Part No.:
- 74LCX139MTR
- Manufacturer:
- STMicroelectronics
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
74LCX139MTR.pdf
- Description:
- IC DECODER/DEMUX 1 X 2:4 16SO
- Quantity:
- Payment:
- Shipping:
Inventory:1,259
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
74LCX139MTR from STMicroelectronics is a low-voltage CMOS dual 2-to-4 decoder/demultiplexer in SO-16 package, operating from 2.0V to 3.6V, with 6.2ns max propagation delay at 3V, 24mA output drive, and 5V-tolerant inputs. It serves as address decoding logic in 3.3V bus interfaces, enabling selective routing of control signals in memory-mapped I/O systems.
For engineers reviewing the 74LCX139MTR datasheet, 74LCX139MTR pinout, 74LCX139MTR application, or 74LCX139MTR equivalent, key selection criteria include input voltage tolerance (0–5.5V), symmetrical output drive (±24mA @ VCC = 3.0–3.6V), propagation delay matching (tPLH ≅ tPHL), and PCI-bus-level compatibility at 24mA load.
Technical Context
The device implements two independent 2-to-4 decoders, each with active-low enable (1G/2G) and dual address inputs (1A/1B, 2A/2B), producing four active-low outputs per section (1Y0–1Y3, 2Y0–2Y3). Its sub-micron C2MOS process enables rail-to-rail 5V-tolerant inputs while maintaining 3.3V core operation.
Propagation delays are balanced (tPLH ≅ tPHL), and output skew is guaranteed ≤1.0ns across all Y outputs under matched loading (CL = 50pF, RL = 500Ω). Power-down protection ensures safe high-impedance behavior during VCC = 0V conditions, with latch-up immunity >500mA per JESD17.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Operating Range | 2.0V to 3.6V - Enables direct integration into 3.3V logic domains without level-shifting. |
| tPD Max | 6.2ns at VCC = 3.0–3.6V, CL = 50pF - Matches AC/ACT-139 speed at half the supply voltage. |
| IOL / IOH Min | 24mA at VCC = 3.0–3.6V - Drives PCI-bus loads and multiple TTL inputs without external buffers. |
| Input Voltage Range | 0V to 5.5V - Accepts 5V logic signals directly, simplifying mixed-voltage system interfacing. |
| Output Skew Max | 1.0ns - Ensures deterministic timing alignment across all four outputs in demux applications. |
| ESD HBM | >2000V - Provides robust handling during board assembly and field service without added protection circuitry. |
| Quiescent ICC | 10µA - Supports ultra-low-power standby modes in battery-backed or energy-sensitive systems. |
Pinout & Package
74LCX139MTR is housed in a 16-pin SOIC (SO-16) package with 1.27mm pitch, RoHS-compliant and ECOPACK® certified. Pin 1 is marked by a beveled corner or dot; pin 8 is GND, pin 16 is VCC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 15 | 1G, 2G - Active-low enable inputs | Gate control for each decoder section; when high, all outputs forced high regardless of address inputs. |
| 2, 3, 13, 14 | 1A, 1B, 2A, 2B - Address inputs | Binary select lines determining which of four outputs goes low; compatible with standard 2-bit address buses. |
| 4–7 | 1Y0 to 1Y3 - Outputs (Section 1) | Active-low decoded outputs; each asserts low for one unique A/B combination when 1G = L. |
| 9–12 | 2Y0 to 2Y3 - Outputs (Section 2) | Independent active-low outputs mirroring Section 1 behavior, controlled by 2G and 2A/2B. |
| 8 | GND | Reference ground for all logic and output stages; requires low-inductance connection to minimize noise coupling. |
| 16 | VCC | Primary power supply (2.0–3.6V); decoupling capacitor (100nF) recommended within 5mm of this pin. |
Key Features
| Feature | Design Value |
|---|---|
| 5V-tolerant inputs | Accepts 0–5.5V input signals while powered from 2.0–3.6V, eliminating level shifters in mixed-supply systems. |
| Symmetrical output drive | IOH = IOL = 24mA min at VCC = 3.0–3.6V - ensures consistent rise/fall times and load driving capability. |
| Power-down protection | Inputs and outputs remain high-impedance and non-latching when VCC = 0V - prevents back-driving or contention on powered subsystems. |
| Latch-up immunity | >500mA per JESD17 - withstands transient overcurrent events without destructive latch-up. |
Applications
| Memory Address Decoding | PCI Bus Interface Logic |
|---|---|
Use Scenario: Selecting one of four SRAM or peripheral chips in a 3.3V microcontroller-based embedded system with legacy 5V-compatible control lines. IC Role / Device Role / Timing Role: Dual decoder maps 2-bit address segments to chip-select lines; active-low outputs directly assert /CS pins with <6.2ns latency. Use Value: Eliminates need for discrete logic or level shifters while meeting tight setup/hold timing budgets for 33MHz PCI-like cycles. | Use Scenario: Enabling individual function blocks (e.g., UART, GPIO, timer) on a multi-peripheral ASIC connected to a 3.3V host bus. IC Role / Device Role / Timing Role: Demultiplexer routes shared control strobes to dedicated peripheral enables; 24mA drive meets PCI bus sink requirements. Use Value: Guarantees signal integrity across 10cm PCB traces loaded with 30pF capacitance and 50Ω termination. |
| Low-Power I/O Expansion | Industrial Control Signal Routing |
Use Scenario: Expanding GPIO count of an ARM Cortex-M0+ MCU in a battery-powered sensor node requiring <15µA sleep current. IC Role / Device Role / Timing Role: Decoder enables one of four isolated digital output drivers; quiescent ICC = 10µA minimizes standby drain. Use Value: Achieves 10-year coin-cell lifetime by reducing static power by 90% versus 5V HC-series alternatives. | Use Scenario: Routing PLC scan-cycle control pulses to four independent solenoid driver modules in a factory automation cabinet. IC Role / Device Role / Timing Role: Dual-section decoding provides fault-isolated enable paths; output skew ≤1.0ns prevents race conditions between actuator triggers. Use Value: Synchronizes mechanical actuation within ±500ps across four channels, critical for coordinated motion sequences. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual 2-to-4 decoder applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVC139ADR | Same pinout and function; lower max tPD (5.5ns @ 3.3V), but only 24mA drive at VCC ≥ 3.0V; no 5V-tolerant inputs. | Requires external level shifters for 5V input sources; better suited for pure 3.3V systems with tighter timing margins. | Select when system uses exclusively 3.3V logic and demands sub-6ns propagation delay. |
| 74AHC139PW | Higher VCC range (2.0–5.5V); 5V-tolerant inputs retained; tPD = 7.1ns @ 5V, but only 8mA drive @ 3.3V. | Compatible with 5V supply rails but lacks PCI-level drive strength at 3.3V; unsuitable for heavy capacitive loads. | Select when full 5V operation is required and output loading remains ≤8mA. |
Compared with SN74LVC139ADR and 74AHC139PW, the 74LCX139MTR uniquely combines 5V-tolerant inputs, 24mA output drive at 3.3V, and balanced propagation delays-making it optimal for mixed-voltage industrial bus interfaces where signal integrity and load driving coexist.
Availability
74LCX139MTR is available at Aetrix Electronics and suitable for memory address decoding, PCI bus interface logic, and low-power I/O expansion requiring stable component supply across extended temperature ranges (–40°C to +85°C).
Supply support for 74LCX139MTR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, analog ICs, power devices, and discrete components for industrial, automotive, and consumer markets.
The 74LCX logic family targets high-speed, low-voltage 3.3V applications with 5V input tolerance-specifically engineered for seamless integration into mixed-signal systems bridging legacy and modern voltage domains.
FAQ
Is 74LCX139MTR pin-compatible with standard 74LS139 or 74HC139?
Yes-74LCX139MTR maintains identical pinout and truth table behavior with 74LS139 and 74HC139, including active-low enables and outputs. However, its 5V-tolerant inputs and 2.0–3.6V VCC range differ from LS (4.75–5.25V) and HC (2.0–6.0V) families, requiring appropriate supply and interface validation.
Can 74LCX139MTR drive a 50Ω transmission line directly?
No-it is not designed as a line driver. With 24mA output current and typical VOH/VOL at 3.3V, it can drive 50Ω loads only under short-trace conditions (<2cm) and low-frequency operation. For reliable 50Ω termination, use a dedicated buffer like SN74LVC1G17 or SN65LVDS1.
What is the maximum capacitive load supported at 6.2ns propagation delay?
The 6.2ns tPD specification is guaranteed with CL = 50pF and RL = 500Ω per test condition in the datasheet. Driving >50pF increases delay nonlinearly; for 100pF loads, measured tPD exceeds 9ns. Use local decoupling and minimize trace length to stay within timing budget.
Does 74LCX139MTR support hot insertion or live swapping?
No-while it features power-down protection (high-Z inputs/outputs at VCC = 0V), it lacks explicit hot-swap circuitry such as slew-rate limiting or undervoltage lockout. Insertion into a live backplane risks transient currents exceeding 50mA absolute maximum ratings and may disrupt bus arbitration.
74LCX139MTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- 74LCX
- 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:
- 24mA, 24mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 2V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SO
74LCX139MTR FAQ
1.How can I place an order for 74LCX139MTR through Aetrix?
Please submit a Request for Quotation (RFQ) for 74LCX139MTR 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 74LCX139MTR reliable?
The price and inventory of 74LCX139MTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LCX139MTR is usually 5 days.
3.What payment methods are accepted for 74LCX139MTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LCX139MTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74LCX139MTR?
74LCX139MTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74LCX139MTR 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 74LCX139MTR?
For technical support, including 74LCX139MTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LCX139MTR requirements.
6.How does Aetrix verify that 74LCX139MTR is sourced from the original manufacturer or authorized distributors?
All 74LCX139MTR 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 74LCX139MTR meets industry standards.
7.What is the process for return or replacement of 74LCX139MTR?
All 74LCX139MTR units undergo pre-shipment inspection (PSI). If there is an issue with 74LCX139MTR, 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 74LCX139MTR part is unused and in its original packaging.
Return procedure for 74LCX139MTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
74LCX139MTR 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 and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
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…
