Texas Instruments SN74LVC139ADR

Overview

SN74LVC139ADR from Texas Instruments is a dual 2-line to 4-line decoder/demultiplexer in SOIC-16 package, operating from 1.65 V to 3.6 V, with max propagation delay of 6.2 ns at 3.3 V and inputs tolerant to 5.5 V. It enables mixed-voltage translation between 3.3-V and 5-V logic domains in address decoding and data routing applications.

For engineers reviewing the SN74LVC139ADR datasheet, SN74LVC139ADR pinout, SN74LVC139ADR application, or SN74LVC139ADR equivalent, key selection criteria include its dual-decoder architecture with active-low enable, 5.5-V-tolerant inputs, sub-7-ns timing at 3.3 V, and SOIC-16 thermal performance (θ_JA = 73°C/W).

Technical Context

This device integrates two independent 2-to-4 line decoders sharing no internal logic coupling-each has dedicated A/B select inputs and active-low G enable. Its fully buffered inputs present only one normalized load, minimizing drive burden on upstream logic.

The decoder supports demultiplexing via G as a data input, with all outputs active-low and mutually exclusive per decoder. Input voltage tolerance up to 5.5 V allows direct interfacing with legacy 5-V TTL without level shifters, while output swing remains rail-to-rail within V_CC (0–V_CC) under specified I_OL/I_OH.

Key Specifications

Pinout & Package

SN74LVC139ADR uses a 16-pin SOIC (D) package measuring 10.4 mm × 5.4 mm × 2.0 mm max height, with gull-wing leads, 1.27 mm pitch, and JEDEC MS-012 compliant outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC139ADR, SN74LV139ADR offers broader supply flexibility but sacrifices speed, while 74AHC139PW delivers superior timing at 5 V but lacks input overvoltage tolerance-making SN74LVC139ADR the optimal choice for mixed 3.3/5-V embedded interfaces requiring both robustness and sub-7 ns latency.

Availability

SN74LVC139ADR is available at Aetrix Electronics and suitable for memory address decoding, peripheral selection logic, bus demultiplexing, and mixed-voltage interface translation requiring stable component supply and long-term industrial availability.

Supply support for SN74LVC139ADR 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 connectivity technologies with over 50 years of innovation in logic, power, and signal chain solutions.

The SN74LVC139ADR belongs to TI's LVC (Low-Voltage CMOS) logic family, engineered for high-speed, low-power, mixed-voltage interoperability in space-constrained industrial and communications equipment.

FAQ

What is the maximum operating frequency supported by SN74LVC139ADR?

The SN74LVC139ADR does not specify a maximum clock frequency directly, but its max propagation delay of 6.2 ns at 3.3 V implies reliable operation up to approximately 80 MHz for address/data switching in decoding applications. Timing margins must account for setup/hold times and board-level signal integrity, especially when driving capacitive loads exceeding 50 pF. The SN74LVC139ADR is not intended for continuous clock distribution.

Can SN74LVC139ADR be used with a 5-V microcontroller output directly?

Yes, SN74LVC139ADR accepts input voltages up to 5.5 V on all A, B, and G pins while powered from 1.65–3.6 V, enabling direct connection to 5-V microcontroller GPIOs without level shifters. This capability is explicitly guaranteed in the datasheet and verified per JESD 22 ESD testing. Outputs remain referenced to V_CC, so they swing 0–V_CC and are compatible with 3.3-V receivers.

Does SN74LVC139ADR support hot insertion or live insertion into a powered system?

No, SN74LVC139ADR is not designed for hot insertion. Its absolute maximum ratings require V_CC to be established before applying input signals, and the device lacks I_off protection or power-off isolation. Applying inputs before V_CC stabilization may cause latch-up or excessive current through input clamps. For hot-swap applications, external protection circuitry or a hot-swap controller is required alongside SN74LVC139ADR.

What is the recommended decoupling strategy for SN74LVC139ADR in high-speed layouts?

Place a 100-nF X7R ceramic capacitor between Pin 16 (GND) and Pin 1 (V_CC) as close as possible to the SOIC-16 package body-no more than 3 mm trace length. Add a 4.7-µF tantalum or aluminum polymer bulk capacitor within 10 mm of the IC for transient current support. Avoid shared vias between GND and V_CC paths; use separate low-inductance connections to the ground plane. This ensures stable operation of SN74LVC139ADR under fast switching conditions.

Is SN74LVC139ADR pin-compatible with older 74LS139 or 74HC139 devices?

No, SN74LVC139ADR is not pin-compatible with 74LS139 or 74HC139. While all three share the same 16-pin SOIC footprint and basic function, pin assignments differ: SN74LVC139ADR places V_CC at Pin 1 and GND at Pin 16, whereas 74LS139 uses Pin 16 for V_CC and Pin 8 for GND. Substituting SN74LVC139ADR without board revision will result in power and ground misconnection and device failure.