Texas Instruments SN74LVT240ADBR

Overview

SN74LVT240ADBR from Texas Instruments is an octal buffer/line driver IC designed for 3.3-V V_CC operation with mixed-mode 5-V TTL interface capability. It features two independent 4-bit channels, separate output-enable (OE) inputs per channel, 3.3-V supply compatibility down to 2.7 V, and I_off/power-up 3-state support for hot insertion in backplane or modular systems.

For engineers reviewing the SN74LVT240ADBR datasheet, SN74LVT240ADBR pinout, SN74LVT240ADBR application, or SN74LVT240ADBR equivalent, key selection criteria include its dual-channel 3-state control, 2.7–3.6-V operating range, ±100 µA I_off at V_CC = 0 V, <4.6 ns propagation delay at 3.3 V, and SSOP-20 package suitability for space-constrained board-level interconnects.

Technical Context

This device implements two independent 4-bit noninverting buffers with active-low OE control per group. Each channel drives data from A inputs to Y outputs when OE is low; outputs enter high-impedance state when OE is high. Power-up 3-state ensures outputs remain disabled during V_CC ramp from 0 to 1.5 V, while I_off blocks current flow when powered down, enabling safe hot insertion into live 5-V buses.

It supports mixed-voltage signaling: 5-V-tolerant inputs and outputs operate with 3.3-V V_CC, enabling direct interfacing between legacy 5-V logic and modern low-voltage systems. Absolute maximum input voltage is 7 V, and output clamp current is rated at ±50 mA - critical for robustness in noisy industrial backplanes.

Key Specifications

Pinout & Package

SN74LVT240ADBR is housed in a 20-pin SSOP (Shrink Small Outline Package), DB package, with 0.65-mm lead pitch, 7.4-mm body width, and 2-mm max height - optimized for high-density PCB layouts requiring mechanical robustness and thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal buffer/line driver applications.

Compared with SN74LVT240ADBR, SN74LVTH240APW sacrifices 5-V interface capability for lower power and cost, while 74ALVC240PW omits I_off and power-up 3-state - making SN74LVT240ADBR uniquely suited for hot-pluggable 3.3-V-to-5-V bridging where bus integrity during insertion is mandatory.

Availability

SN74LVT240ADBR is available at Aetrix Electronics and suitable for backplane interconnects, memory subsystems, modular I/O carriers, and legacy peripheral adapters requiring stable component supply across industrial temperature ranges (−40°C to 85°C).

Supply support for SN74LVT240ADBR 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 industrial-grade reliability validation.

The SN74LVT240ADBR belongs to TI's LVT (Low-Voltage BiCMOS Technology) logic family, engineered specifically for high-speed, mixed-voltage system interfacing in telecom infrastructure, industrial automation, and computing backplanes.

FAQ

What is the maximum input voltage rating for SN74LVT240ADBR?

The SN74LVT240ADBR supports an absolute maximum input voltage of 7 V, enabling direct connection to 5-V TTL signal sources while operating from a 3.3-V supply. This 5-V tolerance is maintained across the full recommended operating temperature range (−40°C to 85°C) and is validated per JEDEC JESD78 latch-up testing.

Does SN74LVT240ADBR support hot insertion, and how is it implemented?

Yes, SN74LVT240ADBR supports hot insertion via two integrated features: I_off circuitry disables outputs and limits current to ±100 µA when V_CC = 0 V, preventing backfeed; and power-up 3-state holds outputs in high-impedance mode during V_CC ramp from 0 to 1.5 V. Both mechanisms are specified and tested per TI's design guidelines for live-backplane applications.

What is the propagation delay of SN74LVT240ADBR at 3.3 V, and how does it vary with load?

At V_CC = 3.3 V and CL = 50 pF, SN74LVT240ADBR exhibits t_PLH = 1.1–3.8 ns and t_PHL = 1.3–4.0 ns. These values are measured under standard test conditions and scale predictably with capacitive load - doubling CL to 100 pF increases delay by ~15–20%, consistent with its 7-pF output capacitance and 64-mA drive strength.

Can SN74LVT240ADBR operate below 3.3 V, and what is the minimum functional V_CC?

Yes, SN74LVT240ADBR is fully specified from 2.7 V to 3.6 V. At V_CC = 2.7 V, it maintains VOL ≤ 0.5 V at I_OL = 24 mA and VOH ≥ 2.4 V at I_OH = −8 mA - meeting TTL output thresholds. This 2.7-V minimum enables use in brownout-prone battery systems without external regulation.

What package type and footprint does SN74LVT240ADBR use, and are soldering guidelines available?

SN74LVT240ADBR uses the SSOP-20 (DB) package: 7.4-mm width, 0.65-mm lead pitch, 2-mm max height. TI provides verified land patterns, stencil designs, and reflow profiles - including MSL Level-1 (260°C peak) handling - on ti.com/package/DB. The package supports standard Type 3 solder paste and IPC-7351-compliant layouts.