Texas Instruments SN74HC139NE4

Overview

SN74HC139NE4 from Texas Instruments is a dual 2-line-to-4-line decoder/demultiplexer in 16-pin PDIP package, operating from 2 V to 6 V, with typical propagation delay of 10 ns at 5 V, ±4-mA output drive, and low ICC of 80 μA max - used for high-speed memory decoding and address demultiplexing in industrial control and instrumentation systems.

For engineers reviewing the SN74HC139NE4 datasheet, SN74HC139NE4 pinout, SN74HC139NE4 application, or SN74HC139NE4 equivalent, this page delivers verified functional modes, real-world timing behavior, confirmed package dimensions, and validated alternative options for legacy through-hole logic design.

Technical Context

The SN74HC139NE4 integrates two independent decoders, each with active-low enable (G) and binary-select inputs (A, B), producing four active-low outputs (Y0–Y3). Each decoder operates as a 2:4 line selector where only one output goes low per input combination when enabled.

It uses CMOS technology with fully buffered inputs, presenting only one normalized load to the driving circuit. The G input doubles as a data line in demultiplexing mode, allowing cascading or gated data routing without external logic.

Key Specifications

Pinout & Package

SN74HC139NE4 uses a 16-pin plastic dual in-line package (PDIP-N), body size 19.31 mm × 6.35 mm, with 0.1-inch lead pitch and through-hole mounting. Pin 1 is marked by a notch or dot; leads are tin-lead (NIPDAU) finish, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC139N and CD74HC139E, the SN74HC139NE4 offers identical decoding performance and mechanical fit but includes TI's enhanced production traceability, RoHS compliance verification, and extended industrial temperature validation - critical for OEMs managing multi-year product lifecycles.

Availability

SN74HC139NE4 is available at Aetrix Electronics and suitable for industrial control, test instrumentation, and legacy system upgrades requiring stable component supply, through-hole assembly compatibility, and long-term obsolescence mitigation.

Supply support for SN74HC139NE4 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 delivering analog, embedded processing, and logic solutions with over 50 years of innovation in industrial, automotive, and communications markets.

The SN74HC139NE4 belongs to TI's HC logic family - designed for high-speed, low-power CMOS compatibility with TTL-level interfaces in cost-sensitive, reliability-critical industrial systems.

FAQ

What is the maximum operating frequency supported by SN74HC139NE4?

The SN74HC139NE4 does not specify a maximum clock frequency because it is a combinational logic device without internal clocking. Its usable speed is determined by propagation delay: 10 ns typical at 5 V, enabling reliable operation in address decode paths up to ~50 MHz. System-level timing must account for input transition times and load capacitance per the switching characteristics table in the SN74HC139NE4 datasheet.

Can SN74HC139NE4 drive LEDs directly?

Yes - SN74HC139NE4 can sink up to 4 mA per output at 5 V, sufficient to illuminate low-current indicator LEDs (e.g., 2 mA @ 1.8 V forward voltage) with a series resistor. For higher-brightness or multi-LED loads, external transistor drivers are recommended. Always verify VOL ≤ 0.33 V at IOL = 4 mA per the SN74HC139NE4 electrical characteristics table.

Is SN74HC139NE4 pin-compatible with SN74LS139?

No - while both are dual 2-to-4 decoders, SN74HC139NE4 uses CMOS technology with different DC characteristics: higher input impedance, rail-to-rail output swing, and lower drive strength than bipolar SN74LS139. Direct substitution requires verifying VIH/VIL thresholds, fanout, and timing margins; level-shifting may be needed in mixed-logic systems using SN74HC139NE4.

What is the purpose of the two enable inputs (G1 and G2) on SN74HC139NE4?

G1 and G2 are independent active-low enables for Decoder 1 and Decoder 2 respectively. When asserted (low), they force all four outputs of that decoder high regardless of A/B inputs. This enables selective activation of either decoder, cascading into larger decode trees (e.g., 3-to-8), or using G as a data line in demultiplexer mode - a key feature confirmed in the SN74HC139NE4 functional description.

Does SN74HC139NE4 require external pull-up resistors on its outputs?

No - SN74HC139NE4 has totem-pole CMOS outputs capable of actively driving high and low states. Pull-ups are unnecessary unless interfacing with open-drain systems or implementing wired-OR logic. The SN74HC139NE4 datasheet specifies VOH ≥ 4.4 V at I OH = −4 mA (VCC = 4.5 V), confirming full rail-swing capability without external components.