Texas Instruments 74LVC1G139DCURG4

Overview

74LVC1G139DCURG4 from Texas Instruments is a single 2-to-4 line decoder IC with active-low outputs, designed for high-speed memory decoding and data routing in 1.65-V to 5.5-V systems. It features 4.9 ns max propagation delay at 3.3 V, ±24-mA output drive, and Ioff support for live insertion. It operates across –40°C to 85°C and is used in low-pin-count address decoding for microcontrollers and FPGAs.

For engineers reviewing the 74LVC1G139DCURG4 datasheet, 74LVC1G139DCURG4 pinout, 74LVC1G139DCURG4 application, or 74LVC1G139DCURG4 equivalent, key selection criteria include its dual-input decode logic, nanoscale US8 (DCU) package, Ioff-enabled partial-power-down capability, and compatibility with mixed-voltage interfaces up to 5.5 V.

Technical Context

This device implements standard 2-to-4 binary decoding with two active-low enable inputs (A and B) controlling four active-low decoded outputs (Y0–Y3). Its logic function follows the truth table where only one output is low per input combination, with all others high.

It uses LVC-series CMOS technology with down-translation support: inputs accept voltages up to 5.5 V regardless of VCC, enabling interfacing with higher-voltage controllers while operating from as low as 1.65 V. The Ioff circuit blocks current flow when VCC = 0, supporting hot-plug and back-drive protection.

Key Specifications

Pinout & Package

74LVC1G139DCURG4 is packaged in an 8-pin US8 (DCU) package - a 1.5-mm × 1.5-mm, 0.5-mm pitch, ultra-thin leadless package with wettable flanks, optimized for space-constrained PCB layouts and automated optical inspection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 2-to-4 decoder applications.

Compared with 74LVC1G139DCURG4, the DCT variant trades miniaturization for assembly simplicity and thermal margin, while the YZP variant further shrinks area but increases PCB routing constraints and inspection requirements - all three share identical logic, timing, and electrical specs.

Availability

74LVC1G139DCURG4 is available at Aetrix Electronics and suitable for industrial sensor hubs, USB-C power delivery subsystems, and FPGA I/O expansion requiring stable component supply, RoHS-compliant packaging, and guaranteed long-term availability.

Supply support for 74LVC1G139DCURG4 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 innovation in low-power, high-reliability IC design.

The SN74LVC1G139 belongs to TI's LVC logic family - engineered for low-voltage operation, mixed-signal interfacing, and space-constrained applications such as portable electronics and modular industrial controllers.

FAQ

What is the logic polarity of the outputs on the 74LVC1G139DCURG4?

The 74LVC1G139DCURG4 features active-low outputs (Y0–Y3). When a valid input combination is applied (e.g., A=0, B=0), the corresponding output goes low while all others remain high. This matches standard 2-to-4 decoder behavior per the function table in the SCES602C datasheet. All outputs default high when inputs are invalid or both A and B are high.

Does the 74LVC1G139DCURG4 support partial power-down operation?

Yes, the 74LVC1G139DCURG4 includes Ioff circuitry that disables outputs and limits off-state current to ±5 µA when VCC = 0 V. This feature enables safe live insertion into powered systems and prevents back-drive damage in partial-power-down scenarios - a key requirement for modular industrial and telecom equipment.

Can the 74LVC1G139DCURG4 interface with 5-V logic while operating from a 1.8-V supply?

Yes, the 74LVC1G139DCURG4 inputs accept voltages up to 5.5 V regardless of VCC, allowing direct connection to 5-V GPIOs or control lines even when powered from 1.8 V. This eliminates external level shifters in mixed-voltage designs and is explicitly confirmed in the "Supports Down Translation to VCC" feature list and Recommended Operating Conditions table.

What is the maximum propagation delay for the 74LVC1G139DCURG4 at 3.3 V?

The maximum propagation delay (tpd) for the 74LVC1G139DCURG4 is 4.9 ns at VCC = 3.3 V, CL = 15 pF, and TA = 25°C, as specified in the Switching Characteristics table of the SCES602C datasheet. This value applies to transitions from either input (A or B) to any output (Y0–Y3) under standard load conditions.

Is the 74LVC1G139DCURG4 pin-compatible with other variants in the SN74LVC1G139 family?

Yes, all SN74LVC1G139 variants - including 74LVC1G139DCURG4 (US8/DCU), 74LVC1G139DCTRG4 (SM8/DCT), and 74LVC1G139YZPR (DSBGA/YZP) - share identical pin numbering and signal assignment. The differences are purely mechanical: package size, pitch, terminal location, and thermal characteristics - not electrical or functional.