Texas Instruments SN74LVTH244AQDBREP

Overview

SN74LVTH244AQDBREP from Texas Instruments is an octal 3-state noninverting buffer/line driver designed for mixed-voltage system interfacing, supporting 5-V TTL inputs and outputs while operating at 3.3-V V_CC, with −40°C to 125°C extended temperature range, I_off hot-insertion support, and bus-hold on all data inputs. It is used in industrial backplane drivers, FPGA I/O expansion, and legacy 5-V logic interfacing to low-voltage microcontrollers.

For engineers reviewing the SN74LVTH244AQDBREP datasheet, SN74LVTH244AQDBREP pinout, SN74LVTH244AQDBREP application, or SN74LVTH244AQDBREP equivalent, key selection criteria include its 3.3-V supply compatibility with 5-V signal tolerance, guaranteed hot-swap capability via I_off and power-up 3-state, bus-hold elimination of external resistors, and SSOP-20 packaging for high-density board layouts.

Technical Context

This device implements two independent 4-bit noninverting buffers, each with dedicated output-enable (OE) control. Its I_off circuitry actively disables outputs during power-down to prevent backflow current, while power-up 3-state ensures outputs remain high-impedance until V_CC stabilizes - critical for live insertion in telecom and server backplanes.

The integrated bus-hold circuit maintains valid logic levels on floating A-inputs without external pull resistors, reducing BOM count and layout complexity. Input transition rate is specified at ≤10 ns/V (enabled), and propagation delay is as low as 0.5 ns (t_PLH/t_PHL) under 3.3-V conditions with 50-pF load.

Key Specifications

Pinout & Package

SN74LVTH244AQDBREP is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65-mm lead pitch, 7.2-mm body width, and JEDEC MO-153 compliant footprint. The package supports reflow soldering per Level-1-260°C-UNLIM MSL rating and offers θ_JA = 70°C/W thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWREP and SN74AHCT244N, SN74LVTH244AQDBREP uniquely combines 3.3-V operation with 5-V signal tolerance, integrated bus-hold, and full hot-swap qualification - making it the sole option for robust, resistor-free, mixed-voltage industrial interfaces requiring −40°C to 125°C reliability.

Availability

SN74LVTH244AQDBREP is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA I/O expansion, telecom line card hot-swap, and automotive diagnostic port isolation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVTH244AQDBREP 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 connectivity technologies, with decades of experience delivering high-reliability logic and interface solutions for industrial and automotive markets.

SN74LVTH244AQDBREP belongs to TI's LVTH (Low-Voltage TTL-High Speed) logic family, engineered specifically for mixed-voltage system interfacing where 3.3-V logic must reliably communicate with legacy 5-V infrastructure.

FAQ

What is the maximum input voltage the SN74LVTH244AQDBREP can tolerate on its A-inputs?

The SN74LVTH244AQDBREP supports input voltages up to 7 V on all data inputs, allowing direct connection to 5-V TTL sources while operating from a 3.3-V supply. This eliminates the need for external level-shifting circuitry and is confirmed in the Absolute Maximum Ratings table (VI = −0.5 V to 7 V). The device maintains this tolerance across its full −40°C to 125°C operating range without derating.

Does the SN74LVTH244AQDBREP require external pullup resistors on its OE pins?

Yes - to ensure outputs remain in high-impedance during power-up and power-down, OE pins must be tied to V_CC through a pullup resistor. The minimum value depends on the current-sinking capability of the driving source, as specified in the datasheet. The SN74LVTH244AQDBREP does not include internal OE pullups, and leaving OE floating risks undefined output states during supply ramping.

Can the SN74LVTH244AQDBREP be used in hot-swap applications?

Yes - the SN74LVTH244AQDBREP is explicitly designed and qualified for hot-insertion. Its I_off circuitry disables outputs when V_CC = 0 V, preventing damaging current backflow, and its power-up 3-state feature guarantees high-impedance outputs until V_CC reaches operational threshold. These capabilities are validated per JEDEC standards and documented in the Functional Description section of the SCAS691C datasheet.

What is the purpose of bus-hold circuitry in the SN74LVTH244AQDBREP?

The bus-hold circuitry in the SN74LVTH244AQDBREP actively maintains valid logic levels (high or low) on unused or floating data inputs without external resistors. It draws ±75 µA at V_CC = 3 V to hold the input near V_CC or GND, eliminating risk of metastability or unintended switching. Using external pull resistors with enabled bus-hold is discouraged, as it creates contention and increases power consumption.

What package type and dimensions does the SN74LVTH244AQDBREP use?

The SN74LVTH244AQDBREP uses a 20-pin SSOP (Shrink Small Outline Package) with package drawing DB, 0.65-mm lead pitch, 7.2-mm body width, and 2.4-mm height. It is supplied in tape-and-reel format (2000 units/reel), qualified to MSL Level-1 (unlimited floor life), and compatible with standard reflow profiles up to 260°C peak temperature.