Texas Instruments SN74LVC139APW

Overview

SN74LVC139APW from Texas Instruments is a dual 2-line to 4-line decoder/demultiplexer in TSSOP-16 package, operating from 1.65 V to 3.6 V, with 6.2 ns max propagation delay at 3.3 V, fully buffered inputs, and 5.5 V-tolerant inputs enabling mixed-voltage translation in 3.3 V/5 V systems.

For engineers reviewing the SN74LVC139APW datasheet, SN74LVC139APW pinout, SN74LVC139APW application, or SN74LVC139APW equivalent, this device serves as a low-voltage, high-speed address decoder for memory expansion, peripheral selection, and logic-level signal routing in space-constrained industrial and embedded control boards.

Technical Context

This IC integrates two independent 2-to-4 line decoders sharing no internal logic coupling; each features active-low enable (G) usable as a data input for demultiplexing. Inputs accept up to 5.5 V regardless of VCC, allowing direct interfacing with legacy 5 V logic while driving 3.3 V loads.

It employs LVC-series CMOS technology with latch-up immunity >250 mA per JESD 17, ESD protection exceeding 2000-V HBM, and output ground bounce <0.8 V at 3.3 V. All unused inputs must be tied to VCC or GND to prevent floating node instability.

Key Specifications

Pinout & Package

TSSOP-16 (PW) package: 4.4 mm × 5.0 mm body, 0.65 mm lead pitch, 1.2 mm max height, gull-wing leads, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV139A and 74LVC139AD, the SN74LVC139APW delivers optimal balance of low-voltage operation, speed, and compact footprint-making it the preferred choice for space-constrained, mixed-voltage embedded designs requiring precise timing control.

Availability

SN74LVC139APW is available at Aetrix Electronics and suitable for industrial control systems, embedded instrumentation, and programmable logic interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74LVC139APW 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 interface and translation ICs.

The SN74LVC139APW belongs to TI's LVC logic family, engineered for low-voltage, high-speed digital interfacing in mixed-signal industrial and automotive-adjacent applications where voltage translation and timing precision are critical.

FAQ

What is the maximum clock frequency supported by SN74LVC139APW in demultiplexer mode?

The SN74LVC139APW does not operate on a clock signal-it is combinational logic. Its usable frequency depends on propagation delay and system timing margins. With a max tpd of 6.2 ns at 3.3 V, it supports reliable operation in address/data paths up to approximately 80 MHz for setup/hold-critical applications, assuming proper PCB layout and load capacitance ≤30 pF. The SN74LVC139APW itself imposes no inherent clock limit.

Can SN74LVC139APW safely interface a 5 V microcontroller with a 3.3 V FPGA?

Yes. The SN74LVC139APW inputs tolerate up to 5.5 V regardless of VCC, allowing direct connection to 5 V GPIOs. Its outputs swing rail-to-rail between GND and VCC (3.3 V), matching LVTTL/LVCMOS 3.3 V input thresholds. No external resistors or translators are needed-this capability is explicitly validated in the SN74LVC139APW datasheet under "Inputs Accept Voltages to 5.5 V".

Does SN74LVC139APW require pull-up or pull-down resistors on unused inputs?

Yes. Per TI's SCBA004 application report and the SN74LVC139APW datasheet, all unused inputs must be held at a defined logic level-either VCC or GND-to prevent floating nodes that cause increased ICC, oscillation, or excessive power dissipation. A 10 kΩ pull-up to VCC or pull-down to GND is recommended; internal weak terminations are not provided.

What is the thermal resistance (θJA) of the SN74LVC139APW in its TSSOP-16 package?

The SN74LVC139APW in the PW (TSSOP-16) package has a junction-to-ambient thermal resistance (θJA) of 108°C/W, as specified in the Absolute Maximum Ratings table. This value assumes standard JEDEC 2-layer board conditions (1-inch² copper pad). For sustained operation near max ratings, thermal relief traces or local copper pours are advised to reduce effective θJA.

Is SN74LVC139APW pin-compatible with older 74LS139 or 74HC139 devices?

No. While functionally equivalent, the SN74LVC139APW uses a different pinout than 74LS139 (which has inverted outputs and different enable polarity) and 74HC139 (which lacks 5.5 V-tolerant inputs and has higher VCC min). The SN74LVC139APW pin mapping matches only other LVC139 variants (e.g., SN74LVC139ADR, SN74LVC139APWR); direct replacement requires PCB redesign unless using identical PW-package predecessors.