Texas Instruments SN74LVTH240DBR

Overview

SN74LVTH240DBR from Texas Instruments is a 3.3-V ABT octal buffer/driver with 3-state outputs, designed for mixed-mode signal operation between 5-V inputs and 3.3-V V_CC. It features bus-hold on all data inputs, I_off support for hot insertion, and operates down to 2.7 V. Used in backplane interface, memory address buffering, and industrial control bus isolation.

For engineers reviewing the SN74LVTH240DBR datasheet, SN74LVTH240DBR pinout, SN74LVTH240DBR application, or SN74LVTH240DBR equivalent, key selection criteria include 3-state output timing (t_PZH ≤ 5.6 ns), bus-hold current (±750 µA), V_CC operating range (2.7–3.6 V), and SSOP-20 thermal performance (θ_JA = 70°C/W).

Technical Context

This device integrates two independent 4-bit noninverting buffers, each with dedicated output-enable (OE) control. The ABT logic family enables TTL-level input compatibility while operating at 3.3-V supply, supporting bidirectional voltage translation without external level shifters.

Active bus-hold circuitry maintains valid logic states on undriven inputs, eliminating need for external pullup/pulldown resistors. I_off and power-up 3-state functionality prevent current backflow and driver conflict during hot insertion or power sequencing.

Key Specifications

Pinout & Package

SN74LVTH240DBR uses a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm pitch, 7.5 mm × 5.6 mm body, and 2.0 mm max height. Pin 1 index area located at top-left corner per JEDEC MO-150.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC240APWR and SN74AHCT240N, SN74LVTH240DBR uniquely combines 5-V input tolerance, bus-hold, I_off, and 3.3-V operation - making it the only choice for robust, mixed-voltage industrial bus buffering requiring zero external biasing and live insertion support.

Availability

SN74LVTH240DBR is available at Aetrix Electronics and suitable for industrial control, factory automation, and embedded computing applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74LVTH240DBR 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 for industrial, automotive, and communications markets.

The SN74LVTH240DBR belongs to TI's ABT logic family, engineered for mixed-voltage system interfacing with emphasis on hot-plug reliability, bus integrity, and simplified board-level design in harsh environments.

FAQ

What is the maximum operating temperature range for SN74LVTH240DBR?

The SN74LVTH240DBR is rated for operation from −40°C to +85°C ambient temperature. This industrial-grade range supports deployment in factory-floor controllers, outdoor telemetry units, and other environments where extended thermal stability is required. The SSOP-20 package's θ_JA of 70°C/W allows for predictable thermal derating under continuous load conditions.

Does SN74LVTH240DBR require external pullup resistors on its inputs?

No, SN74LVTH240DBR does not require external pullup or pulldown resistors on its data inputs due to integrated bus-hold circuitry. Each input actively maintains its last-valid logic state with ±750 µA hold current. Using external resistors with bus-hold is explicitly discouraged in the datasheet as it may cause contention or excessive current draw.

Can SN74LVTH240DBR be used in hot-swap applications?

Yes, SN74LVTH240DBR is explicitly designed for hot-insertion applications. Its I_off circuitry disables outputs when V_CC = 0 V, preventing back-current flow, and its power-up 3-state feature ensures outputs remain high-impedance during power ramp-up - both critical for safe live module replacement in backplane systems.

What is the output drive capability of SN74LVTH240DBR at 3.3 V?

At V_CC = 3.3 V, SN74LVTH240DBR delivers up to 64 mA sink current (I_OL) and 32 mA source current (I_OH). This drive strength supports standard TTL loads and enables reliable fanout to multiple downstream devices while maintaining VOL ≤ 0.55 V and VOH ≥ 2.0 V under full load.

Is SN74LVTH240DBR compatible with 5-V logic inputs?

Yes, SN74LVTH240DBR supports 5-V tolerant inputs - its VI rating extends to 5.5 V, and it correctly interprets TTL-level thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V) even when powered from 3.3 V. This eliminates the need for external level translators when interfacing with legacy 5-V microcontrollers or peripherals.