Texas Instruments SN74ABT240ADBR

Overview

SN74ABT240ADBR from Texas Instruments is an octal inverting buffer/driver with 3-state outputs, designed for memory address and bus interface applications. It features high-drive capability (–32 mA IOH, 64 mA IOL), Ioff support for partial-power-down operation, and operates over –40°C to 85°C. Its SSOP-20 package enables dense PCB layouts in industrial control and data acquisition systems.

For engineers reviewing the SN74ABT240ADBR datasheet, SN74ABT240ADBR pinout, SN74ABT240ADBR application, or SN74ABT240ADBR equivalent, key selection criteria include output drive strength, 3-state enable timing (tPZH/tPLZ ≤ 5.2 ns), Ioff leakage (< ±100 µA at VCC = 0), and SSOP-20 thermal performance (θJA = 70°C/W).

Technical Context

This device implements two independent 4-bit inverting buffers, each with dedicated active-low output-enable (OE) inputs. Logic inversion occurs only when OE is low; outputs enter high-impedance state when OE is high. The architecture supports bidirectional bus isolation and avoids contention during power sequencing.

Designed for 5-V TTL-compatible systems, it meets JEDEC JESD-17 latch-up immunity (>500 mA) and exceeds JESD22 ESD ratings (2000-V HBM, 200-V MM). Its Ioff circuitry actively disables outputs during power-down, preventing backflow current when VCC = 0 and VI/VO ≤ 4.5 V.

Key Specifications

Pinout & Package

SN74ABT240ADBR uses a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm lead pitch and 7.4 mm × 5.3 mm body size. The package is RoHS-compliant, moisture-sensitive Level-1, and optimized for automated surface-mount assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ABT240ADBR, the SOIC-20 alternative offers superior thermal performance for sustained high-current operation, while the SOP-20 variant prioritizes mechanical compatibility over worst-case Ioff margin-both retain identical logic behavior and timing.

Availability

SN74ABT240ADBR is available at Aetrix Electronics and suitable for industrial control, test equipment, and data acquisition systems requiring stable component supply and long-term manufacturability.

Supply support for SN74ABT240ADBR 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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability and industrial-grade performance.

The ABT logic family-including SN74ABT240ADBR-is engineered for high-speed, high-drive 5-V bus interfacing in mission-critical industrial and instrumentation applications.

FAQ

What is the maximum output current capability of SN74ABT240ADBR?

The SN74ABT240ADBR delivers up to 64 mA sink current (IOL) and –32 mA source current (IOH) per output. This high drive strength allows direct connection to multiple TTL inputs or termination resistors without external amplification, making SN74ABT240ADBR ideal for driving heavy capacitive loads in bus architectures.

Does SN74ABT240ADBR support partial-power-down operation?

Yes, SN74ABT240ADBR includes Ioff circuitry that disables outputs when VCC = 0, limiting leakage to ±100 µA. This feature prevents damaging current backflow when the device is powered down but input/output buses remain active-critical for hot-swap and modular system designs using SN74ABT240ADBR.

What is the recommended pullup resistor value for OE pins on SN74ABT240ADBR?

Texas Instruments recommends tying OE pins to VCC through a pullup resistor to ensure high-impedance state during power-up. The minimum value depends on the driver's current-sinking capability; for standard 5-V CMOS drivers, a 4.7-kΩ resistor is typical. This design practice guarantees safe default state before firmware initializes OE control in systems using SN74ABT240ADBR.

How does SN74ABT240ADBR handle ground bounce during switching?

SN74ABT240ADBR limits typical output ground bounce (VOLP) to <1 V at VCC = 5 V and TA = 25°C. This low bounce specification results from optimized output stage design and internal grounding, reducing noise coupling into adjacent signal paths-a key advantage in mixed-signal systems where SN74ABT240ADBR buffers timing-critical address or control buses.

Is SN74ABT240ADBR pin-compatible with other packages in the ABT240 family?

Yes, all ABT240 variants-including SN74ABT240ADBR (SSOP-20), SN74ABT240ADWR (SOIC-20), and SN74ABT240ANSR (SOP-20)-share identical 20-pin assignments and logic functionality. Mechanical differences exist in package dimensions and thermal characteristics, but PCB layout changes are not required when migrating between these SN74ABT240ADBR-compatible footprints.