Texas Instruments SN74LVT244BGQNR

Overview

SN74LVT244BGQNR from Texas Instruments is an octal 3-state noninverting buffer/line driver designed for 3.3-V VCC operation with 5-V tolerant inputs and outputs, supporting mixed-mode signal interfacing between 3.3-V logic and 5-V systems. It features two independent 4-bit sections with separate output-enable (OE) controls, 2.7-V to 3.6-V supply range, ±100 µA Ioff, and hot-insertion support via power-up 3-state and Ioff circuitry. Used in backplane bus interface and voltage-level translation applications.

For engineers reviewing the SN74LVT244BGQNR datasheet, SN74LVT244BGQNR pinout, SN74LVT244BGQNR application, or SN74LVT244BGQNR equivalent, key selection criteria include its dual 4-bit 3-state architecture, 5-V input/output compatibility at 3.3-V VCC, Ioff-enabled hot-swap capability, low ground bounce (<0.8 V), and VFBGA-20 (GQN) package thermal performance (θJA = 78°C/W).

Technical Context

The SN74LVT244BGQNR implements TTL-compatible input thresholds (VIL = 0.8 V, VIH = 2 V) while operating from a 3.3-V supply, enabling direct connection to 5-V buses without level shifters. Its dual-section architecture isolates control paths: 1OE enables Y1–Y4, 2OE enables Y1'–Y4', allowing independent gating of two 4-bit data lanes.

Hot-insertion robustness is achieved through two complementary mechanisms: Ioff limits current backflow when VCC = 0 V (±100 µA), and power-up 3-state forces outputs into high-impedance during VCC ramp-up (200 µs/V compliance). Output drive strength is asymmetric-64 mA sink (IOL) vs. 32 mA source (IOH)-optimized for driving terminated transmission lines in bus environments.

Key Specifications

Pinout & Package

VFBGA-20 (GQN) package: 2.5 mm × 3.0 mm, 0.5-mm ball pitch, bottom-side solder balls, JEDEC MO-225 variation BC compliant. Exposed die pad enhances thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWR and SN74ALVC244PWR, the SN74LVT244BGQNR uniquely delivers 5-V output drive capability, Ioff-enabled hot-swap robustness, and guaranteed 2.7-V operation - making it the only option among the three qualified for mixed-voltage backplane interfaces requiring live insertion.

Availability

SN74LVT244BGQNR is available at Aetrix Electronics and suitable for backplane bus interface, industrial I/O expansion, hot-swappable module interface, and voltage-level translation applications requiring stable component supply across extended temperature ranges (−40°C to 85°C).

Supply support for SN74LVT244BGQNR 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets since 1930.

The SN74LVT244BGQNR belongs to TI's LVT (Low-Voltage BiCMOS Technology) logic family, engineered specifically for mixed-voltage system interfacing with emphasis on hot-swap reliability, 5-V signal compatibility, and low-noise 3.3-V operation.

FAQ

What is the minimum VCC voltage required for reliable operation of the SN74LVT244BGQNR?

The SN74LVT244BGQNR is fully specified down to 2.7 V VCC per the recommended operating conditions table. At this voltage, it maintains valid VOH (≥2.4 V), VOL (≤0.5 V), and tPD (≤3.8 ns) while supporting 5-V input tolerance. Operation below 2.7 V may result in undefined logic thresholds or increased propagation delay, and is not guaranteed by TI's datasheet.

Does the SN74LVT244BGQNR support true 5-V output drive, or only 5-V input tolerance?

The SN74LVT244BGQNR supports true 5-V output drive: its outputs are rated for VO = −0.5 V to 7 V in high-impedance or power-off states, and −0.5 V to VCC + 0.5 V when active - meaning at VCC = 3.3 V, outputs swing up to 3.8 V, compatible with 5-V TTL input thresholds. However, it does not source 5-V rail voltage; it translates 3.3-V logic levels to 5-V system-compatible signaling.

How is hot-insertion supported in the SN74LVT244BGQNR, and what external components are required?

The SN74LVT244BGQNR supports hot-insertion via integrated Ioff (prevents backflow when VCC = 0) and power-up 3-state (forces outputs high-Z during VCC ramp-up). To ensure safe power-up, OE pins must be tied to VCC through a pullup resistor; TI recommends ≥10 kΩ for standard CMOS drivers, sized to limit current while guaranteeing OE remains high until VCC stabilizes.

What is the thermal performance of the SN74LVT244BGQNR in its GQN package, and how does it affect maximum output current?

The SN74LVT244BGQNR in the VFBGA-20 (GQN) package has a junction-to-ambient thermal resistance (θJA) of 78°C/W. At 85°C ambient and 3.6-V VCC, continuous 64-mA per-output operation raises junction temperature by ~50°C - within the 125°C max rating. Derating is required above 60°C ambient if all eight outputs drive 64 mA simultaneously.

Can unused inputs on the SN74LVT244BGQNR be left floating, or must they be terminated?

Unused inputs on the SN74LVT244BGQNR must not be left floating. TI explicitly requires all unused inputs to be tied to VCC or GND to prevent oscillation, excessive ICC, or undefined logic states. This is documented in Note 5 of the datasheet and reinforced in TI application report SCBA004 on slow/floating CMOS inputs.