Texas Instruments SN74LVT244BDBR

Overview

SN74LVT244BDBR 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 dual 4-bit drivers with independent output-enable (OE) controls, supports hot insertion via I_off and power-up 3-state, and operates down to 2.7 V for unregulated battery systems.

For engineers reviewing the SN74LVT244BDBR datasheet, SN74LVT244BDBR pinout, SN74LVT244BDBR application, or SN74LVT244BDBR equivalent, key selection considerations include its 20-pin SSOP (DB) package, 3.3-V supply compatibility with 5-V TTL interfacing, low ground bounce (<0.8 V), and JESD 78 Class II latch-up performance.

Technical Context

The SN74LVT244BDBR implements two independent 4-bit noninverting buffer sections, each controlled by a dedicated OE input (1OE and 2OE). When OE is low, data passes from A inputs to Y outputs; when high, outputs enter high-impedance state. Its ABT (Advanced BiCMOS Technology) architecture enables fast switching with t_PLH/t_PHL ≤ 3.5 ns at V_CC = 3.3 V and CL = 50 pF.

Designed for hot-insertion, it integrates I_off circuitry to block current backflow during power-down and power-up 3-state logic to hold outputs in high-Z during supply ramping. Absolute maximum ratings allow VI up to 7 V and VO up to 7 V in high-Z state, supporting robust interfacing in mixed-voltage systems.

Key Specifications

Pinout & Package

SN74LVT244BDBR uses a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm pitch and 7.4 mm × 5.3 mm body size (JEDEC MO-150). Pin 1 index area located at top-left corner; pin numbering follows standard counter-clockwise layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH244APWRE4 and 74ALVC244PW,118, the SN74LVT244BDBR uniquely combines 5-V input tolerance, 64 mA drive, and sub-4 ns speed in a production-qualified SSOP package - making it optimal for mixed-voltage bus isolation where reliability and timing margin are critical.

Availability

SN74LVT244BDBR is available at Aetrix Electronics and suitable for PCI interface design, memory subsystem buffering, hot-swappable backplane modules, and industrial I/O expansion requiring stable component supply across extended temperature ranges (−40°C to +85°C).

Supply support for SN74LVT244BDBR 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 over 90 years of innovation in industrial, automotive, and communications markets.

The SN74LVT244BDBR belongs to TI's ABT logic family, engineered for high-speed, mixed-voltage interfacing in mission-critical infrastructure where signal integrity, hot-swap capability, and long-term supply stability are essential.

FAQ

What is the maximum input voltage the SN74LVT244BDBR can tolerate?

The SN74LVT244BDBR supports an input voltage range of −0.5 V to 7 V per absolute maximum ratings. This allows direct connection to 5-V TTL signals while operating at 3.3-V V_CC, enabling seamless mixed-voltage interfacing without external level shifters. The device maintains this tolerance across its full operating temperature range (−40°C to +85°C).

Does the SN74LVT244BDBR support hot insertion, and how is it implemented?

Yes, the SN74LVT244BDBR supports hot insertion through two integrated features: I_off circuitry disables outputs during power-down to prevent damaging back-current, and power-up 3-state logic holds outputs in high-impedance during V_CC ramp-up. These functions are inherent to the ABT process and require no external components - verified per JESD 78 Class II latch-up and JESD 22 ESD standards.

What is the thermal resistance (θ_JA) of the SN74LVT244BDBR in its SSOP package?

The SN74LVT244BDBR in the SSOP (DB) package has a junction-to-ambient thermal resistance (θ_JA) of 70°C/W, measured per JESD 51-7 on a standard 2-layer JEDEC test board. This value assumes proper PCB copper pour and decoupling; actual thermal performance improves with enhanced heatsinking or multi-layer board designs.

Can unused inputs on the SN74LVT244BDBR be left floating?

No, all unused inputs on the SN74LVT244BDBR must be tied to V_CC or GND to ensure proper device operation and prevent increased ICC or erratic behavior. This requirement is specified in TI application report SCBA004 and applies to both data (A) and control (OE) inputs. Floating inputs may cause excessive current draw or oscillation due to CMOS input stage sensitivity.

What is the minimum recommended pull-up resistor value for the OE pins of the SN74LVT244BDBR?

The minimum pull-up resistor value for OE pins depends on the current-sinking capability of the driving source. TI recommends sizing the resistor so that the voltage drop across it keeps OE above V_IH (2.0 V min) when driven low. For typical 3.3-V logic drivers with 8-mA sink capability, a 10-kΩ resistor provides sufficient margin while minimizing quiescent current - confirmed in the SN74LVT244BDBR functional description and application guidance.