Texas Instruments SN74LVTH240DW

Overview

SN74LVTH240DW 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 bus isolation in industrial control systems.

For engineers reviewing the SN74LVTH240DW datasheet, SN74LVTH240DW pinout, SN74LVTH240DW application, or SN74LVTH240DW equivalent, key selection criteria include 3-state enable timing (t_PZH/t_PZL ≤ 6.7 ns), output drive strength (I_OL = 64 mA), bus-hold current (±750 µA), and SOIC-20 thermal performance (θ_JA = 58°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.

Bus-hold circuitry actively maintains valid logic states on undriven inputs, eliminating need for external pullup/pulldown resistors. I_off and power-up 3-state functionality ensure safe hot-insertion by disabling outputs during power transitions and preventing backflow current.

Key Specifications

Pinout & Package

SN74LVTH240DW uses a 20-pin SOIC (DW) package, 7.5 mm × 12.8 mm body, 1.27 mm lead pitch, 2.65 mm max height, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC240APW and SN74AHCT240N, SN74LVTH240DW uniquely combines 3.3-V operation, 64 mA drive, bus-hold, and I_off-making it the only option for robust mixed-voltage hot-plug bus interfaces in industrial control.

Availability

SN74LVTH240DW is available at Aetrix Electronics and suitable for industrial control panels, programmable logic controller (PLC) backplanes, and embedded memory subsystems requiring stable component supply and long-term manufacturability.

Supply support for SN74LVTH240DW 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 for industrial, automotive, and communications markets.

The SN74LVTH240DW belongs to TI's ABT logic family, engineered specifically for reliable mixed-voltage bus interfacing in harsh industrial environments with hot-swap and floating-input challenges.

FAQ

What is the maximum operating temperature range for SN74LVTH240DW?

The SN74LVTH240DW is rated for operation from −40°C to +85°C ambient temperature. This industrial-grade range supports deployment in factory automation, motor control cabinets, and outdoor telecom infrastructure where thermal cycling and extended temperature exposure occur. The SOIC-20 package's θ_JA of 58°C/W allows sustained operation within this range under typical PCB copper pour conditions.

Does SN74LVTH240DW require external pullup resistors on its inputs?

No, SN74LVTH240DW 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 enabled may cause excessive current draw or logic instability and is explicitly discouraged in the datasheet.

Can SN74LVTH240DW safely interface between a 3.3-V microcontroller and a 5-V peripheral?

Yes, SN74LVTH240DW supports mixed-mode operation: its inputs accept 5-V logic levels while powered from a 3.3-V V_CC, and its outputs tolerate 5-V signals in high-impedance or driven states. This enables direct connection to 5-V peripherals without external level shifters, provided output loading remains within I_OL = 64 mA and I_OH = −32 mA limits.

What is the recommended power-up sequence for SN74LVTH240DW?

OE pins should be tied to V_CC through a pullup resistor (value determined by driver sink capability) to ensure outputs remain in high-impedance state during power ramp-up. The datasheet specifies a minimum V_CC ramp rate of 200 µs/V to guarantee proper power-up 3-state behavior. Avoid floating OE pins, as this may cause undefined output states during startup.

Is SN74LVTH240DW pin-compatible with other packages in the same family?

SN74LVTH240DW (SOIC-20) shares identical pinout and function with SN74LVTH240DBR (SSOP-20), SN74LVTH240NSR (SOP-20), and SN74LVTH240PWR (TSSOP-20). All variants use the same top-side marking "LVTH240" and match the DW package's pin assignments for 1OE, 1A1–1A4, 1Y1–1Y4, V_CC, GND, 2OE, 2A1–2A4, and 2Y1–2Y4 - enabling drop-in replacement across footprint families.