Texas Instruments 74ACT11139D

Overview

74ACT11139D from Texas Instruments is a dual 2-line-to-4-line decoder/demultiplexer IC designed for high-speed memory decoding and data routing. It features two independent decoders, TTL-compatible inputs, fully buffered inputs (1 normalized load each), and operates over −40°C to 85°C at 4.5–5.5 V supply. Used in high-performance memory systems to minimize decoding latency.

For engineers reviewing the 74ACT11139D datasheet, 74ACT11139D pinout, 74ACT11139D application, or 74ACT11139D equivalent, this page delivers verified electrical specs, SOIC-16 pin mapping, functional truth table alignment, and real-world use cases in synchronous address decoding and demux-based data distribution.

Technical Context

The 74ACT11139D implements two fully independent 2:4 decoders with active-low enables (1G, 2G) usable as demux data lines. Each decoder has fully buffered inputs-each presenting only one normalized load-to reduce fanout burden on driving logic. Its EPIC™ 1-µm CMOS process ensures high noise immunity and latch-up resistance (500 mA typical at 125°C).

Propagation delays are tightly specified: tPLH/tPHL from A/B inputs to outputs range 1.7–8.5 ns (VCC = 5 V); enable-to-output delays are 1.8–7.9 ns. Center-pin VCC/GND configuration minimizes high-speed switching noise, supporting stable operation in dense memory subsystems.

Key Specifications

Pinout & Package

74ACT11139D is housed in a 16-pin plastic small-outline integrated circuit (SOIC) package (D package), 300-mil width, with center-aligned VCC (Pin 16) and GND (Pin 8) to suppress simultaneous switching noise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74ACT11139D, 74ACT139D offers identical timing and drive but less explicit input compatibility documentation, while SN74LV139ADR trades speed and drive strength for wider voltage range and lower static power-making it appropriate only in non-critical timing paths.

Availability

74ACT11139D is available at Aetrix Electronics and suitable for high-speed memory decoding, synchronous data demultiplexing, and industrial bus arbitration requiring stable component supply and long-term industrial temperature support.

Supply support for 74ACT11139D 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 decades of heritage in high-reliability industrial and computing components.

The 74ACT11139D belongs to TI's advanced CMOS (ACT) logic family, engineered specifically for high-speed memory-decoding and data-routing applications demanding minimal propagation delay and robust noise immunity.

FAQ

What is the maximum operating frequency supported by the 74ACT11139D?

The 74ACT11139D does not specify a maximum clock frequency directly, but its propagation delay (1.7–8.5 ns) supports reliable operation in systems with address setup/hold windows ≥10 ns. In practice, it enables memory decode for CPUs running at ≥100 MHz where decode latency must be sub-cycle. The 74ACT11139D achieves this via EPIC™ process optimization and center-pin power/ground layout.

Does the 74ACT11139D require external pull-up or pull-down resistors on unused inputs?

Yes - per the datasheet's Note 3, unused or floating inputs on the 74ACT11139D must be held high or low to prevent increased ICC, noise susceptibility, or undefined output states. This applies to all inputs (1A, 1B, 1G, 2A, 2B, 2G). Leaving them unconnected risks erratic behavior and elevated power consumption in the 74ACT11139D.

Can the 74ACT11139D be used as a 1-of-4 demultiplexer?

Yes - the 74ACT11139D functions as two independent 1-of-4 demultiplexers. With 1G or 2G used as the data input and 1A/1B or 2A/2B as select lines, each decoder routes a single active-high signal to one of four outputs. This capability is explicitly stated in the device description and confirmed by the function table, making the 74ACT11139D suitable for data distribution tasks beyond pure decoding.

What is the meaning of "EPIC™" in the 74ACT11139D datasheet?

EPIC™ (Enhanced-Performance Implanted CMOS) is Texas Instruments' proprietary 1-µm CMOS fabrication process used for the 74ACT11139D. It delivers high-speed performance, 500-mA latch-up immunity at 125°C, and improved noise margins. This process underpins the 74ACT11139D's sub-10-ns delays and industrial temperature rating, distinguishing it from older bipolar or standard CMOS logic families.

Is the 74ACT11139D pin-compatible with the 74LS139 or 74HC139?

No - the 74ACT11139D is not pin-compatible with 74LS139 or 74HC139. While all are dual 2:4 decoders, the 74ACT11139D uses a unique pinout: outputs are interleaved (1Y0–1Y3 on left, 2Y0–2Y3 on right), with VCC at Pin 16 and GND at Pin 8. In contrast, 74LS139 and 74HC139 place VCC at Pin 16 but GND at Pin 8 *only in some variants*, and output ordering differs. Always verify against the 74ACT11139D pin diagram before board reuse.