Texas Instruments SN74HC139PWG4

Overview

SN74HC139PWG4 from Texas Instruments is a dual 2-line-to-4-line decoder/demultiplexer in TSSOP-16 package, operating from 2 V to 6 V with typical propagation delay of 10 ns at 5 V and ±4-mA output drive capability. It features two independent decoders, each with active-low enable (G) for cascading or data gating, and is used in high-speed memory decoding and address demultiplexing in embedded control systems.

For engineers reviewing the SN74HC139PWG4 datasheet, SN74HC139PWG4 pinout, SN74HC139PWG4 application, or SN74HC139PWG4 equivalent, key selection criteria include its dual-decoder architecture, low ICC (80 μA max), LSTTL-load compatibility (up to 10 loads), and TSSOP-16 footprint suitability for space-constrained PCB layouts.

Technical Context

The SN74HC139PWG4 implements two independent CMOS-based 2-to-4 line decoders with fully buffered inputs and active-low enable per channel. Each decoder asserts exactly one low output (Y0–Y3) based on binary input A/B when G is low; all outputs go high when G is high.

Its logic conforms to standard HC-series voltage thresholds (VIH = 3.15 V min at VCC = 4.5 V, VIL = 1.35 V max), supports 50-pF load switching, and maintains stable operation across −40°C to +85°C ambient temperature with thermal resistance RθJA = 108°C/W in TSSOP package.

Key Specifications

Pinout & Package

TSSOP-16 package (5.00 mm × 4.40 mm, 1.2 mm max height), RoHS-compliant, NIPDAU lead finish, MSL Level-1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC139PWR, SN74HC139PWG4 offers identical functionality and reliability; versus 74HC139D, it delivers tighter timing control and superior thermal performance in compact industrial PCBs.

Availability

SN74HC139PWG4 is available at Aetrix Electronics and suitable for industrial control panels, embedded instrumentation, and programmable logic interfaces requiring stable component supply and long-term manufacturability.

Supply support for SN74HC139PWG4 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 over 90 years of innovation in industrial, automotive, and communications markets.

The SN74HC139PWG4 belongs to TI's 74HC logic family, designed for high-speed, low-power digital interfacing in memory systems, data routing, and control logic where predictable timing and wide supply tolerance are critical.

FAQ

What is the maximum operating frequency supported by SN74HC139PWG4?

The SN74HC139PWG4 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 (12 ns max at 6 V) and load capacitance. For reliable operation with 50-pF loads, input signal transitions should be limited to <10 MHz repetition to avoid cumulative timing skew across cascaded stages. The SN74HC139PWG4 itself imposes no inherent frequency ceiling beyond these timing constraints.

Can SN74HC139PWG4 operate at 3.3 V supply voltage?

Yes, SN74HC139PWG4 operates reliably at 3.3 V supply voltage. Its recommended operating range is 2 V to 6 V, and input thresholds scale proportionally (VIH ≥ 2.31 V, VIL ≤ 0.99 V at 3.3 V). Output VOH/VOL specifications are guaranteed across this range, making SN74HC139PWG4 compatible with 3.3-V LVTTL and mixed-voltage systems without level translation.

What is the function of pins 8 and 9 on SN74HC139PWG4?

Pins 8 and 9 on SN74HC139PWG4 are no-connect (NC) terminals - they are not bonded to the die and serve no electrical function. TI's datasheet explicitly defines them as NC, and the device operates correctly with these pins left unconnected. Routing traces or placing vias on these pads is unnecessary and may risk mechanical interference during assembly.

How does the active-low enable (G) input affect output states in SN74HC139PWG4?

When the G input is high (logic 1), all four Y outputs of that decoder channel are forced high regardless of A/B inputs - effectively disabling the channel. When G is low (logic 0), the decoder functions normally: one Y output goes low corresponding to the binary value of A/B (00→Y0, 01→Y1, etc.), while the other three remain high. This enables hierarchical decoding or data gating in demultiplexer configurations.

Is SN74HC139PWG4 suitable for automotive applications?

SN74HC139PWG4 is not AEC-Q200 qualified and is designated for industrial use (−40°C to +85°C). For automotive applications, TI offers the pin-compatible SN74HC139-Q1, which undergoes extended temperature testing (−40°C to +125°C), failure analysis, and PPAP documentation. Using SN74HC139PWG4 in automotive contexts requires full system-level qualification and is not recommended for safety-critical or production vehicle ECUs.