Texas Instruments SN74HC139DRG4

Overview

SN74HC139DRG4 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 microcontroller-based systems.

For engineers reviewing the SN74HC139DRG4 datasheet, SN74HC139DRG4 pinout, SN74HC139DRG4 application, or SN74HC139DRG4 equivalent, key selection criteria include its dual-decoder architecture, low-power CMOS design (80 μA max ICC), 10 ns tpd at 5 V, and compatibility with LSTTL loads - critical for timing-sensitive address routing in embedded controllers and FPGA I/O expansion.

Technical Context

The SN74HC139DRG4 implements two fully buffered, independent 2-to-4 line decoders sharing no internal logic; each has dedicated A/B select inputs and active-low G enable. When G is high, all four outputs (Y0–Y3) are forced high regardless of A/B state; when G is low, only one output goes low per binary input combination (00→Y0, 01→Y1, etc.). Inputs present only one normalized load, minimizing fanout burden on driving logic.

Its switching behavior is characterized under CL = 50 pF, with tpd ranging from 12 ns (6 V) to 47 ns (2 V), and output transition time (tt) as low as 6 ns at 6 V. The device supports wide supply tolerance and operates across –40°C to +85°C, making it suitable for industrial-grade digital control and interface logic where deterministic decode timing is required.

Key Specifications

Pinout & Package

TSSOP-16 package (PW), 5.00 mm × 4.40 mm body size, 0.65 mm pitch, 1.2 mm max height, RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC139DR and 74HC139D,118, the SN74HC139DRG4 offers optimal trade-off between miniaturized packaging, full 6 V tolerance, and industrial temperature range - making it the default choice for new designs targeting cost-effective, space-constrained embedded control.

Availability

SN74HC139DRG4 is available at Aetrix Electronics and suitable for industrial control systems, microcontroller peripheral expansion, FPGA I/O staging, and memory address decoding requiring stable component supply and long-term lifecycle support.

Supply support for SN74HC139DRG4 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 high-reliability electronic components.

The SN74HC139 series belongs to TI's industry-standard 74HC logic family, designed specifically for high-speed, low-power digital interface and decoding tasks in industrial, computing, and communications equipment.

FAQ

What is the maximum supply voltage rating for SN74HC139DRG4?

The absolute maximum supply voltage for SN74HC139DRG4 is 7 V, but the recommended operating range is 2 V to 6 V per TI SCLS108E. Operating continuously above 6 V risks exceeding electrical characteristics limits and may degrade long-term reliability. For robust 5 V system design, the 6 V upper bound provides margin against rail overshoot during switching transients.

Does SN74HC139DRG4 support 3.3 V logic levels?

Yes, SN74HC139DRG4 fully supports 3.3 V operation: VIH(min) = 2.0 V and VIL(max) = 0.8 V at VCC = 3.3 V, meeting standard 3.3 V CMOS input thresholds. Its outputs swing rail-to-rail (VOH ≥ 3.1 V, VOL ≤ 0.26 V at 4 mA load), ensuring interoperability with 3.3 V microcontrollers and FPGAs without level-shifting circuitry.

How many independent decoders are integrated in SN74HC139DRG4?

SN74HC139DRG4 contains two completely independent 2-line-to-4-line decoders in one TSSOP-16 package. Each decoder has dedicated A/B select inputs and active-low G enable, with no shared internal nodes - allowing asynchronous operation and fault isolation between channels.

What is the typical propagation delay of SN74HC139DRG4 at 5 V?

The typical propagation delay (tpd) of SN74HC139DRG4 is 10 ns at VCC = 5 V, CL = 50 pF, and TA = 25°C, as specified in TI's SCLS108E datasheet. This value applies to both A/B → Y and G → Y transitions, enabling predictable timing in synchronous address decode and demux applications.

Can SN74HC139DRG4 drive standard TTL loads directly?

Yes, SN74HC139DRG4 can drive up to 10 LSTTL loads per output, verified by its ±4 mA output drive capability at 5 V and compatible voltage thresholds (VOH ≥ 3.98 V, VOL ≤ 0.26 V). This eliminates need for buffer stages when interfacing with legacy TTL peripherals or discrete transistor switches.