Texas Instruments 74AC11240DWR

Overview

74AC11240DWR from Texas Instruments is an octal inverting buffer/line driver with dual 4-bit sections, 3-state outputs, and separate active-low output-enable (OE) inputs. It operates from –40°C to 85°C at VCC = 3–5.5 V, delivers ±24 mA output drive, and features 5.4 ns typical propagation delay (VCC = 5 V). It is used in memory address buffering, clock distribution, and bus transceivers where flow-through pinout minimizes PCB trace crossovers.

For engineers reviewing the 74AC11240DWR datasheet, 74AC11240DWR pinout, 74AC11240DWR application, or 74AC11240DWR equivalent, key selection criteria include symmetrical OE control per section, high-speed switching noise suppression via center-pin VCC/GND, latch-up immunity (500 mA at 125°C), and compatibility with 3.3 V and 5 V logic systems.

Technical Context

The 74AC11240DWR implements two independent 4-bit inverting buffers, each with dedicated active-low OE input controlling high-impedance output states. Its EPIC (Enhanced-Performance Implanted CMOS) 1-µm process enables rail-to-rail output swing, low input capacitance (4 pF), and low power dissipation capacitance (12 pF when disabled).

It supports mixed-voltage interfacing across 3 V, 4.5 V, and 5.5 V supply conditions, with VIH/VIL thresholds scaling proportionally (e.g., VIH = 3.15 V at VCC = 4.5 V). Input transition rate limits (0–5 ns/V for OE, 0–10 ns/V for data) ensure reliable timing under fast-edge conditions without false triggering.

Key Specifications

Pinout & Package

74AC11240DWR uses a 24-pin plastic small-outline (DW) package with 300-mil body width and gull-wing leads. Pin layout follows flow-through architecture: inputs on left, outputs on right, VCC/GND centered for low-noise decoupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal inverting buffer applications.

Compared with SN74AC240N and 74LVC240APW, the 74AC11240DWR uniquely combines 3–5.5 V operation, DW package flow-through routing, and industrial temperature support - making it optimal for new industrial bus interface designs requiring layout efficiency and voltage flexibility.

Availability

74AC11240DWR is available at Aetrix Electronics and suitable for memory address buffering, clock distribution, and parallel bus transceiver applications requiring stable component supply, long-term industrial lifecycle support, and consistent DW-package sourcing.

Supply support for 74AC11240DWR 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 industry-standard logic families.

The 74AC11240DWR belongs to TI's Advanced CMOS (AC) logic series, designed for high-speed, low-noise digital interfacing in industrial, computing, and communications infrastructure where signal integrity and thermal robustness are critical.

FAQ

What is the operating voltage range for the 74AC11240DWR?

The 74AC11240DWR operates over a supply voltage range of 3 V to 5.5 V. This allows direct interoperability with both 3.3 V and 5 V logic systems without external level-shifting circuitry. The device's input thresholds scale with VCC (e.g., VIH = 0.7 × VCC), ensuring consistent noise margin across the full range. Absolute maximum VCC is 6 V, but sustained operation above 5.5 V is not recommended.

Does the 74AC11240DWR support hot insertion or live insertion into a powered backplane?

The 74AC11240DWR is not explicitly rated for hot insertion. While its absolute maximum ratings include input clamp current (±20 mA) and output clamp current (±50 mA), the datasheet does not specify hot-swap qualification or I²t survivability. For live-insertion applications, external protection (e.g., series resistors, TVS diodes) and controlled ramp-up sequencing are recommended. The 74AC11240DWR should be powered before applying input signals in standard use.

How many output-enable (OE) inputs does the 74AC11240DWR have, and how are they assigned?

The 74AC11240DWR has two independent active-low output-enable inputs: 1OE (pin 13) controls the first 4-bit section (1A1–1A4 → 1Y1–1Y4), and 2OE (pin 24) controls the second 4-bit section (2A1–2A4 → 2Y1–2Y4). This dual-OE architecture enables selective activation of either 4-bit group, supporting time-multiplexed bus access or partial bus isolation - a key differentiator from single-OE octal buffers like the 74AC240.

What is the typical propagation delay of the 74AC11240DWR at 5 V supply?

At VCC = 5 V and TA = 25°C, the 74AC11240DWR exhibits a typical propagation delay of 5.4 ns for both tPLH and tPHL (input A to output Y). The maximum specified delay is 7.5 ns under recommended operating conditions. These values are measured with CL = 50 pF and account for process, voltage, and temperature variation - confirming suitability for ≤100 MHz clock or data distribution.

Is the 74AC11240DWR pin-compatible with the 74ACT11240 or 74F11240?

No, the 74AC11240DWR is not pin-compatible with 74ACT11240 or 74F11240. Although all three share the same logic function and 24-pin DW package footprint, the 74ACT11240 uses different input threshold specifications (TTL-compatible VIH), and the 74F11240 is a bipolar FAST family part with distinct DC parameters and timing behavior. Pin assignments match only within the AC family; substituting across families risks timing violations or excessive power draw.