Texas Instruments SN74ACT240PWR

Overview

SN74ACT240PWR from Texas Instruments is an octal 3-state inverting buffer/driver IC operating at 4.5V–5.5V V_CC, with TTL-compatible inputs, 8.5ns max propagation delay at 5V, and ±24mA output drive. It serves as a bidirectional bus interface or memory address driver in compact digital systems.

For engineers reviewing the SN74ACT240PWR datasheet, SN74ACT240PWR pinout, SN74ACT240PWR application, or SN74ACT240PWR equivalent, key selection criteria include its TSSOP-20 package footprint, dual 4-bit enable-controlled inversion logic, 5V supply tolerance, and compatibility with legacy 5V TTL and CMOS buses in space-constrained designs.

Technical Context

The SN74ACT240PWR implements two independent 4-bit inverting buffer sections, each with dedicated active-low output-enable (1OE, 2OE) control. Its CMOS push-pull outputs deliver balanced sourcing and sinking capability (±24mA), enabling robust signal integrity on shared data or address lines.

It operates strictly within 4.5V–5.5V V_CC, accepts input voltages up to 5.5V regardless of supply, and maintains high-impedance outputs when OE is high-critical for bus arbitration and hot-swap isolation in network switches and handset baseband subsystems.

Key Specifications

Pinout & Package

TSSOP-20 package (PW), 6.5mm × 6.4mm body size, 1.2mm max height, lead pitch 0.65mm, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state inverting buffer applications.

Compared with SN74ACT240DWR, SN74ACT240PWR saves >50% board area but requires controlled reflow; versus SN74LVC240APWR, it retains full 5V system compatibility at the cost of slightly higher propagation delay and static current.

Availability

SN74ACT240PWR is available at Aetrix Electronics and suitable for smartphone baseband interfaces, industrial network switch backplanes, and wearable health sensor hubs requiring stable component supply across production lifecycles.

Supply support for SN74ACT240PWR 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 connectivity solutions, with decades of expertise in logic and interface ICs.

The SNx4ACT240 family was designed for high-density 5V bus interfacing in memory, clock, and data-path applications-emphasizing speed, drive strength, and robust 3-state control in compact packages.

FAQ

What is the maximum operating temperature for SN74ACT240PWR?

The SN74ACT240PWR is rated for operation from –40°C to +85°C. This industrial temperature range ensures reliable performance in smartphone baseband modules, network switch chassis, and wearable sensor hubs exposed to ambient thermal cycling. The TSSOP-20 package's thermal resistance (R_θJA = 126.2°C/W) requires adequate PCB copper pour for sustained high-current operation.

Does SN74ACT240PWR support 3.3V logic inputs?

Yes, SN74ACT240PWR accepts 3.3V logic inputs reliably because its input thresholds (V_IL ≤ 0.8V, V_IH ≥ 2.0V) are TTL-compatible and its inputs tolerate up to 5.5V-well above 3.3V. However, it must be powered at 4.5V–5.5V; it does not operate from a 3.3V supply rail.

Can SN74ACT240PWR replace SN74LS240 in existing designs?

SN74ACT240PWR can functionally replace SN74LS240 in most 5V systems due to matching pinout, inverting 3-state behavior, and TTL-compatible inputs. Key advantages include higher drive (±24mA vs. ±15mA), faster speed (8.5ns vs. 15ns), and CMOS power efficiency-but verify V_OH/V_OL margins under load, as ACT outputs swing closer to rails than LS.

What is the recommended power supply decoupling for SN74ACT240PWR?

Place a 0.1µF ceramic capacitor between V_CC (Pin 20) and GND (Pin 10) as close as possible to the SN74ACT240PWR package. For systems with heavy simultaneous switching, add a 4.7µF–10µF bulk capacitor nearby. This suppresses supply noise induced by the ±24mA output transitions and maintains stable 5V regulation during fast edge rates.

Is SN74ACT240PWR pin-compatible with other TSSOP-20 logic buffers?

SN74ACT240PWR uses the industry-standard TSSOP-20 footprint (JEDEC MO-153), making it mechanically compatible with other PW-packaged TI logic devices like SN74ACT541PWR or SN74ACT244PWR. However, logic function (inverting vs. non-inverting), enable polarity, and internal channel grouping differ-electrical verification is required before substitution.