Texas Instruments 74AC11240DWRG4

Overview

74AC11240DWRG4 from Texas Instruments is an octal inverting buffer/line driver with dual 4-bit sections, active-low 3-state outputs, and flow-through pinout architecture. It operates from 3 V to 5.5 V, delivers ±24 mA output drive at 5 V, supports –40°C to 85°C industrial temperature range, and features symmetrical OE control for bus isolation in memory address and clock distribution systems.

For engineers reviewing the 74AC11240DWRG4 datasheet, 74AC11240DWRG4 pinout, 74AC11240DWRG4 application, or 74AC11240DWRG4 equivalent, key selection criteria include guaranteed 3-state timing (tPZH ≤ 9.2 ns at 5 V), high noise immunity via center-pin VCC/GND, EPIC CMOS process latch-up resistance (500 mA typical), and DW package thermal performance (1.7 W max).

Technical Context

This device implements two independent 4-bit inverting buffers, each with dedicated active-low output-enable (OE) inputs. Data propagation is strictly inverting (A → Y), and 3-state control is synchronous-outputs enter high-impedance only when OE is high. No internal logic combines sections; they operate as electrically isolated functional blocks.

Designed using Texas Instruments' EPIC 1-μm CMOS process, it achieves low input capacitance (4 pF), low output capacitance (10 pF), and rail-to-rail output voltage swing (VOH ≥ 4.94 V, VOL ≤ 0.44 V at VCC = 5.5 V, IOL = 24 mA). Absolute maximum ratings permit operation up to 6 V supply and –65°C to 150°C storage.

Key Specifications

Pinout & Package

74AC11240DWRG4 uses a 24-pin SOIC (DW) package with 300-mil body width and gull-wing leads. Pin numbering follows standard JEDEC MS-013, with VCC (pins 14, 15, 16, 17) and GND (pins 1, 2, 3, 4) centrally located to suppress ground bounce.

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 74AC11240DWRG4 uniquely combines flow-through routing, center-pin power/ground, and 500 mA latch-up immunity - making it the only option among the three qualified for high-reliability industrial bus buffering with minimal PCB layout overhead.

Availability

74AC11240DWRG4 is available at Aetrix Electronics and suitable for memory address buffering, clock distribution networks, and industrial I/O expansion requiring stable component supply, long-term lifecycle support, and consistent parametric performance across temperature extremes.

Supply support for 74AC11240DWRG4 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 founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The 74AC logic family was engineered for high-speed, low-power CMOS compatibility with TTL interfaces, targeting industrial control, instrumentation, and legacy system upgrades where reliability and pin-level interoperability are critical.

FAQ

What logic function does the 74AC11240DWRG4 implement?

The 74AC11240DWRG4 implements two independent 4-bit inverting buffers, each with active-low 3-state output enable (OE). When OE is low, inputs A1–A4 or A1'–A4' pass through inverted to outputs Y1–Y4 or Y1'–Y4'; when OE is high, outputs go high-impedance. It does not perform level shifting or voltage translation - input and output logic thresholds track VCC.

Is the 74AC11240DWRG4 pin-compatible with standard 74AC240 devices?

No - the 74AC11240DWRG4 is not pin-compatible with generic 74AC240 variants. It uses a 24-pin DW package with flow-through pinout (inputs on left, outputs on right, dual OE and duplicated VCC/GND), whereas standard 74AC240s use 20-pin packages (DIP, SOIC, TSSOP) with interleaved I/O. The 74AC11240DWRG4 requires a unique footprint and layout.

What is the maximum operating frequency supported by the 74AC11240DWRG4?

The 74AC11240DWRG4 does not specify a maximum clock frequency directly, but its propagation delay (tPLH/tPHL ≤ 7.5 ns at 5 V) and 3-state timing (tPHZ ≤ 6.6 ns) support reliable operation in systems with data/address toggle rates up to approximately 100 MHz, assuming proper load capacitance (≤50 pF) and controlled-impedance routing.

Does the 74AC11240DWRG4 support mixed-voltage operation (e.g., 3.3 V inputs driving 5 V outputs)?

No - the 74AC11240DWRG4 is a single-supply device: all inputs and outputs reference the same VCC pin. It accepts 3.3 V or 5 V logic levels only when VCC matches that supply. For mixed-voltage interfacing, external level shifters or dual-supply translators are required; the 74AC11240DWRG4 itself provides no voltage translation capability.

How does the center-pin VCC/GND configuration improve noise performance in the 74AC11240DWRG4?

The 74AC11240DWRG4 places four VCC and four GND pins centrally in the 24-pin DW package to minimize ground loop inductance and power distribution impedance. This layout reduces simultaneous switching noise (SSN) by shortening return current paths and decoupling high-frequency transients - verified by TI's characterization showing <10 mV SSN at 100 MHz toggle under 50 pF load.