Texas Instruments SN74LVTH540DW

Overview

SN74LVTH540DW from Texas Instruments is an octal buffer/driver IC designed for 3.3-V V_CC operation with 5-V tolerant inputs and outputs, supporting mixed-mode signal interfacing between 3.3-V logic and 5-V systems. It features dual active-low 3-state enable inputs (OE1/OE2), bus-hold on all eight data inputs, I_off protection, and operates down to 2.7 V for unregulated battery applications.

For engineers reviewing the SN74LVTH540DW datasheet, SN74LVTH540DW pinout, SN74LVTH540DW application, or SN74LVTH540DW equivalent, this device is selected for bus driving, memory address buffering, and hot-pluggable backplane interfaces where level translation, output isolation, and input stability without external resistors are required.

Technical Context

The SN74LVTH540DW implements noninverting octal buffering with a 2-input AND gate control structure for its 3-state outputs: both OE1 and OE2 must be low to enable outputs; either high forces all Y1–Y8 into high-impedance. Its bus-hold circuitry actively maintains valid logic states on undriven A1–A8 inputs, eliminating external pullup/pulldown resistors.

It supports hot insertion via I_off (±100 µA at V_CC = 0) and power-up 3-state behavior, ensuring outputs remain high-Z during power ramping from 0 to 1.5 V and when V_CC is below operational threshold. Absolute maximum ratings include 7-V input/output tolerance and −0.5 V to 4.6 V V_CC, enabling robust interfacing in mixed-voltage environments.

Key Specifications

Pinout & Package

SN74LVTH540DW uses a 20-pin SOIC (DW) package measuring 13.0 mm × 7.6 mm × 2.65 mm (max height), with standard JEDEC MS-013 outline and RoHS-compliant NiPdAu lead finish. Pin 1 index is located at top-left corner with notch marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH540DW, SN74LVC540APW reduces cost and power but sacrifices 5-V interface capability and bus-hold convenience, while 74ALVC540MTCX improves timing margin at the expense of system-level robustness in mixed-voltage or hot-swap scenarios.

Availability

SN74LVTH540DW is available at Aetrix Electronics and suitable for memory address buffering, backplane bus driving, and industrial I/O expansion requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for SN74LVTH540DW 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 over 50 years of innovation in high-reliability interface and power management ICs.

The SN74LVTH540DW belongs to TI's LVTH logic family, engineered for mixed-voltage system interconnect-specifically targeting 3.3-V core logic interfacing with legacy 5-V peripherals in industrial, telecom, and computing infrastructure.

FAQ

What is the recommended operating voltage range for SN74LVTH540DW?

The SN74LVTH540DW is specified to operate reliably from 2.7 V to 3.6 V on V_CC. Operation below 2.7 V may cause undefined output states or increased propagation delay, while exceeding 3.6 V violates absolute maximum ratings and risks permanent damage. The device supports unregulated battery input down to 2.7 V without performance degradation.

Does SN74LVTH540DW require external pullup resistors on its inputs?

No, SN74LVTH540DW does not require external pullup or pulldown resistors on A1–A8 because it integrates active bus-hold circuitry. This feature maintains valid logic levels on unused or floating inputs using ±500 µA dynamic current, eliminating BOM components and improving noise immunity in high-density layouts.

Can SN74LVTH540DW safely interface with 5-V logic devices?

Yes, SN74LVTH540DW supports true mixed-mode operation: its inputs and outputs tolerate up to 5.5 V regardless of V_CC level, allowing direct connection to 5-V TTL/CMOS sources and loads while powered from a 3.3-V supply. This eliminates external level-shifting circuitry in hybrid-voltage systems.

How does SN74LVTH540DW support hot insertion in backplane systems?

SN74LVTH540DW supports hot insertion through two key mechanisms: I_off circuitry disables outputs when V_CC = 0, blocking damaging back-current flow, and power-up 3-state ensures outputs remain high-Z during V_CC ramp from 0 to 1.5 V-preventing bus contention before system initialization completes.

What is the thermal resistance (θ_JA) of SN74LVTH540DW in its SOIC-DW package?

The SN74LVTH540DW in the SOIC-DW package has a junction-to-ambient thermal resistance (θ_JA) of 58 °C/W, measured per JESD 51-7. This value assumes standard JEDEC 2S2P board layout; actual thermal performance depends on PCB copper area, airflow, and adjacent heat sources-derating is required above 85°C ambient.