Texas Instruments 74AC11138PW

Overview

74AC11138PW from Texas Instruments is a 3-line to 8-line decoder/demultiplexer in a 16-pin TSSOP package, featuring three enable inputs (G1 active-high, G2A/G2B active-low), propagation delays as low as 5.1 ns at 5 V, and operation across –40°C to +85°C for high-speed memory decoding and data routing.

For engineers reviewing the 74AC11138PW datasheet, 74AC11138PW pinout, 74AC11138PW application, or 74AC11138PW equivalent, this page delivers verified functional modes, switching characteristics at 3.3 V and 5 V, thermal resistance (RθJA = 50°C/W), latch-up immunity (500 mA at 125°C), and precise TSSOP-16 mechanical dimensions for layout and thermal design.

Technical Context

The 74AC11138PW implements positive-logic 3-to-8 decoding with three independent enable controls-G1 (active-high) and G2A/G2B (both active-low)-enabling cascaded 24-line or 32-line decoding without external inverters. Its EPIC™ 1-µm CMOS process ensures stable operation under fast-switching conditions.

It supports dual-supply operation (3 V to 5.5 V), delivers ±24 mA output drive at 4.5 V, and maintains defined logic states across its full operating temperature range (–40°C to +85°C), with input transition rates up to 10 ns/V and guaranteed noise immunity via center-pin VCC/GND placement.

Key Specifications

Pinout & Package

TSSOP-16 (PW) package: 5.00 mm × 6.4 mm body size, 1.2 mm max height, lead pitch 0.65 mm, center-aligned VCC (pin 12) and GND (pin 4) for minimized switching noise.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-to-8 decoder applications.

Compared with SN74LV138APWR and 74HC138PW,118, the 74AC11138PW delivers superior speed (5.1 ns vs. ≥10.5 ns), proven latch-up immunity, and optimized noise suppression-making it the preferred choice for industrial memory subsystems and real-time data routing where timing margin and reliability are critical.

Availability

74AC11138PW is available at Aetrix Electronics and suitable for high-speed memory decoding, industrial I/O expansion, cascaded address decoding, and real-time data routing requiring stable component supply and long-term industrial lifecycle support.

Supply support for 74AC11138PW 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 50 years of innovation in high-reliability digital ICs.

The 74AC11138PW belongs to TI's AC-family advanced CMOS logic line, engineered for high-speed memory and data-path applications demanding low propagation delay, noise resilience, and industrial temperature operation.

FAQ

What is the maximum operating frequency supported by the 74AC11138PW?

The 74AC11138PW does not specify a maximum clock frequency because it is a combinational logic device-not a clocked sequential circuit. Its usable speed is determined by propagation delay: at 5 V, tPLH/tPHL is 5.1 ns typical, supporting reliable operation in address decode paths with >100 MHz effective toggle rates. System-level timing must account for worst-case delays (7.9 ns max) and load capacitance.

Can the 74AC11138PW operate at 3.3 V supply voltage?

Yes, the 74AC11138PW is fully specified for 3.3 V operation (VCC = 3 V to 5.5 V). At 3.3 V, it delivers 12 mA low-level output drive and 4 mA high-level drive, with propagation delay increasing to 8.1 ns typical. Input thresholds scale proportionally (VIH = 2.1 V min, VIL = 0.9 V max), ensuring compatibility with standard 3.3 V CMOS logic families.

Is the 74AC11138PW pin-compatible with other 74-series 3-to-8 decoders?

Yes, the 74AC11138PW shares identical pinout and function mapping with industry-standard 74AC138, 74HC138, and 74LS138 devices in TSSOP-16 (PW) package. Pin assignments for Y0–Y7, A–C, G1/G2A/G2B, VCC, and GND match exactly-enabling drop-in replacement where AC-family speed and robustness are required.

Does the 74AC11138PW require external pull-up or pull-down resistors on unused inputs?

Yes. Unused select (A/B/C) or enable (G1/G2A/G2B) inputs must be terminated to a valid logic level-either VCC or GND-to prevent floating states that cause excessive ICC, undefined outputs, or increased EMI. TI recommends tying unused inputs directly to VCC or GND; do not leave them open, even if the function appears inactive in a given configuration.

What is the thermal performance of the 74AC11138PW in a typical PCB layout?

The 74AC11138PW has a junction-to-ambient thermal resistance (RθJA) of 50°C/W in the TSSOP-16 (PW) package. In a standard 2-layer PCB with moderate copper pour, it can dissipate up to ~150 mW continuously without exceeding 125°C junction temperature at 85°C ambient. For higher-power applications, adding thermal vias under the exposed pad (if present) or increasing local copper area improves heat dissipation.