Texas Instruments SN74LVC1G139DCUR

Overview

SN74LVC1G139 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 dual address inputs (A, B), four independent active-low outputs (Y0–Y3), 4.9 ns max propagation delay at 3.3 V/15 pF, ±24-mA output drive at 3.3 V, and Ioff support for live insertion and partial-power-down operation.

For engineers reviewing the SN74LVC1G139 datasheet, SN74LVC1G139 pinout, SN74LVC1G139 application, or SN74LVC1G139 equivalent, this device serves as a compact, low-power, voltage-tolerant decoder for address decoding in SSDs, AV receivers, HD TVs, and video analytics servers - where fast enable timing, bus contention control, and overvoltage-safe inputs are critical.

Technical Context

The SN74LVC1G139 implements a combinational 2-bit binary decoder with MSB input B and LSB input A, producing one asserted low output per unique input combination (Y0 = !B·!A, Y1 = !B·A, Y2 = B·!A, Y3 = B·A). All outputs are open-drain compatible due to rail-to-rail CMOS output structure and support down-translation to VCC.

Its Ioff circuitry actively disables outputs during power-down, blocking reverse current flow when VCC = 0 V while inputs or outputs remain biased up to 5.5 V. Propagation delays are tightly matched across outputs (<1 ns skew at 3.3 V), enabling synchronous multi-output activation in timing-critical decode paths.

Key Specifications

Pinout & Package

VSSOP-8 (DCU) package: 2.30 mm × 2.00 mm body, 0.5-mm lead pitch, exposed pad not present, RoHS-compliant NiPdAu/Sn lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G139, SN74LVC1G138DCKR adds decoding depth at the cost of layout overhead, while 74AUP1G139GW,125 trades speed and drive for lower quiescent current - making SN74LVC1G139 the optimal balance of performance, density, and robustness for mainstream embedded decode tasks.

Availability

SN74LVC1G139 is available at Aetrix Electronics and suitable for SSDs, AV receivers, and HD TVs requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for SN74LVC1G139 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 expertise in high-reliability, low-power logic families.

The SN74LVC1G139 belongs to TI's LVC (Low-Voltage CMOS) logic portfolio, engineered for voltage-flexible, high-speed digital interfacing in consumer, industrial, and computing applications where space, power, and timing precision are critical.

FAQ

What is the maximum operating frequency supported by the SN74LVC1G139?

The SN74LVC1G139 does not specify a maximum clock frequency because it is a combinational logic device without internal clocking. Its usable switching rate is determined by propagation delay (4.9 ns max at 3.3 V) and load capacitance. For a 15-pF load, it supports clean transitions up to ~100 MHz under typical conditions, but system-level timing must account for board trace delays and signal integrity.

Can the SN74LVC1G139 operate with a 1.8-V supply and interface with 3.3-V inputs?

Yes. The SN74LVC1G139 supports VCC from 1.65 V to 5.5 V and accepts input voltages up to 5.5 V regardless of VCC level. At VCC = 1.8 V, inputs at 3.3 V meet VIH/VIL specifications and trigger correct decoding - enabling direct level-shifting between 1.8-V logic domains and higher-voltage peripherals without external components.

Does the SN74LVC1G139 support wired-OR output configurations?

No. The SN74LVC1G139 has push-pull CMOS outputs, not open-drain. Its outputs actively drive both high and low states. To implement wired-OR, external pull-up resistors and diode-or logic would be required - but this is not recommended due to timing skew and increased power. Use open-drain alternatives like SN74LVC1G07 if wired-OR is essential.

How does the Ioff feature protect the SN74LVC1G139 during partial power-down?

When VCC = 0 V, the Ioff circuitry disables all outputs, limiting leakage current to ±5 µA even if inputs or outputs are biased to 5.5 V. This prevents damaging reverse current flow from powered downstream circuits into the unpowered SN74LVC1G139, satisfying JEDEC JESD78 Class II latch-up immunity and enabling safe live insertion in modular systems.

What is the thermal resistance (RθJA) of the SN74LVC1G139 in the DCU package?

The SN74LVC1G139 in the VSSOP-8 (DCU) package has a junction-to-ambient thermal resistance (RθJA) of 195°C/W, measured under standard JEDEC JESD51-2 conditions. This value assumes a 1-in² 2-oz copper pad with two vias; actual board-level performance depends on PCB layout, copper area, and airflow.