Texas Instruments SN74AHC139DGVR

Overview

SN74AHC139DGVR from Texas Instruments is a dual 2-to-4 line decoder/demultiplexer in TVSOP-16 package, operating from 2 V to 5.5 V, with propagation delays as low as 4.4 ns (VCC = 5 V, CL = 15 pF), balanced CMOS 3-state outputs, and active-low enable inputs per channel-used for memory address decoding and data routing in high-speed embedded systems.

For engineers reviewing the SN74AHC139DGVR datasheet, SN74AHC139DGVR pinout, SN74AHC139DGVR application, or SN74AHC139DGVR equivalent, key selection criteria include supply voltage range (2–5.5 V), output drive capability (±8 mA at 5 V), propagation delay vs. load capacitance, ESD robustness (2000 V HBM), and TVSOP-16 footprint compatibility with space-constrained PCB layouts.

Technical Context

The SN74AHC139DGVR implements two independent 2:4 decoders, each with two address inputs (A1, A0) and one active-low enable (G). Outputs are active-low and open-drain compatible only when externally pulled up-though internally driven push-pull-enabling chip-select generation for up to eight peripheral devices across both channels.

Its logic operates on positive-logic decoding: when G is low, outputs Y0–Y3 reflect the binary state of A1A0 (e.g., A1A0 = 10 → Y2 low); when G is high, all four outputs go high-impedance. This enables cascading via enable chaining and supports demultiplexing by using G as data input and A1A0 as select lines.

Key Specifications

Pinout & Package

SN74AHC139DGVR uses a 16-pin Thin Very Small Outline Package (TVSOP) with 0.5 mm pitch, body size 3.6 mm × 4.4 mm, and total footprint 3.6 mm × 6.4 mm - optimized for high-density PCBs where SOIC or TSSOP would consume excess area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar decoder/demultiplexer applications.

Compared with SN74LV139APWR, SN74AHC139DGVR delivers 40% faster propagation at 5 V and tighter VIH/VIL margins; compared with 74AHC139D,118, it reduces PCB area by 57% while maintaining full functional and timing equivalence-making SN74AHC139DGVR optimal for space-constrained, high-speed digital systems.

Availability

SN74AHC139DGVR is available at Aetrix Electronics and suitable for industrial control panels, automotive infotainment head units, and medical diagnostic equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74AHC139DGVR 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets since 1930.

The SN74AHC139DGVR belongs to TI's AHC logic family-designed for high-speed, low-power, TTL-compatible CMOS operation in memory and data-path applications where propagation delay, noise immunity, and wide supply range are critical.

FAQ

What is the maximum capacitive load SN74AHC139DGVR can drive while meeting datasheet timing specifications?

The SN74AHC139DGVR is characterized for load capacitances up to 50 pF in switching specifications (e.g., tPLH/tPHL). At CL = 50 pF and VCC = 5 V, propagation delay remains ≤10.5 ns. Driving >50 pF increases delay nonlinearly and may cause marginal timing in high-frequency systems; for heavier loads, buffer stages or reduced clock rates are recommended. The SN74AHC139DGVR itself does not specify a hard capacitive limit beyond datasheet test conditions.

Can SN74AHC139DGVR outputs be safely wired together for increased drive strength?

Yes-both channels of the SN74AHC139DGVR can have corresponding outputs (e.g., 1Y0 and 2Y0) paralleled to double sink/source current capacity, provided identical input signals are applied to both A1/A0 and G pins. This configuration maintains logic integrity and is explicitly supported in TI's application guidance. Do not parallel outputs across different decode states or enable conditions, as contention will occur.

Does SN74AHC139DGVR support 1.8 V logic level interfacing?

No-SN74AHC139DGVR has a minimum VCC of 2 V and is not guaranteed to operate reliably at 1.8 V. Input thresholds scale with VCC; at 1.8 V, VIH would fall below 1.3 V, risking misreads. For 1.8 V systems, consider SN74LV139APWR (1.65–5.5 V range) or level-shifting buffers. The SN74AHC139DGVR requires ≥2 V supply to meet all AC/DC specifications.

How should unused inputs on SN74AHC139DGVR be terminated?

All unused inputs (e.g., A0, A1, or G on either channel) must be tied to a valid logic level-either VCC or GND-using direct connection or a 10 kΩ pull-up/down resistor. Floating CMOS inputs cause undefined output states, increased ICC, and potential oscillation. TI's layout guidelines explicitly require termination; leaving inputs unconnected violates absolute maximum ratings and risks device malfunction.

Is SN74AHC139DGVR pin-compatible with older 74LS139 or 74HC139 variants?

SN74AHC139DGVR shares identical pinout and logic function with 74HC139 and 74HCT139 in TVSOP-16, but differs electrically: AHC offers higher speed, lower power, and wider VCC range than HC/HCT. It is not pin-compatible with 74LS139 (TTL, different voltage thresholds, SOIC-16 only). Always verify VCC, VIH/VIL, and timing margins before drop-in replacement-SN74AHC139DGVR is a functional upgrade, not a direct TTL substitute.