Texas Instruments SN74LV244ATRGYR

Overview

SN74LV244ATRGYR from Texas Instruments is an octal noninverting buffer/driver with 3-state outputs, designed for memory-address, clock, and bus-oriented applications. It operates from 4.5 V to 5.5 V, features TTL-voltage-compatible inputs, Ioff partial-power-down support, typical propagation delay of 5.4 ns at 5 V, and low output ground bounce (<0.8 V).

For engineers reviewing the SN74LV244ATRGYR datasheet, SN74LV244ATRGYR pinout, SN74LV244ATRGYR application, or SN74LV244ATRGYR equivalent, key selection considerations include 3-state bus driving capability, VQFN-20 thermal performance (θJA = 37°C/W), mixed-mode voltage operation support, and Ioff-enabled system-level power sequencing.

Technical Context

The SN74LV244ATRGYR implements two independent 4-bit noninverting buffers, each with dedicated output-enable (OE) control. Its logic diagram confirms direct A→Y signal path when OE is low, and high-impedance Y-state when OE is high - enabling bidirectional bus isolation without inversion.

It integrates Ioff circuitry that disables outputs during power-down, preventing backflow current when VCC = 0 V while inputs remain biased. Input thresholds (VIH = 2 V, VIL = 0.8 V) are TTL-compatible across the full 4.5–5.5 V supply range, and dynamic noise margins (VOLP < 0.8 V, VOHV > 2.3 V) ensure robust switching in noisy digital systems.

Key Specifications

Pinout & Package

VQFN-20 package (RGY), 3.5 mm × 4.5 mm, 0.5 mm pitch, exposed thermal pad (Pin 21), 1 mm max height. Requires soldering of thermal pad for mechanical stability and thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWR and 74LVX244M, SN74LV244ATRGYR uniquely combines 5-V operation, Ioff protection, and VQFN thermal efficiency - making it the optimal choice for new 5-V embedded systems requiring robust hot-swap capability and compact layout.

Availability

SN74LV244ATRGYR is available at Aetrix Electronics and suitable for memory subsystems, microcontroller peripheral interfaces, industrial backplanes, and digital signal distribution networks requiring stable component supply and long-term manufacturability.

Supply support for SN74LV244ATRGYR 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 SN74LV244ATRGYR belongs to TI's LV logic family, engineered for high-speed, low-noise 5-V digital interfacing with emphasis on bus integrity, power sequencing resilience, and thermal efficiency in space-constrained applications.

FAQ

What is the recommended power-up sequence for SN74LV244ATRGYR?

TI specifies that OE pins must be held high (via pullup resistor to VCC) during power-up to guarantee outputs remain in high-impedance state until supply stabilizes. For SN74LV244ATRGYR, use a ≤10-kΩ pullup to VCC on both 1OE and 2OE. This prevents bus contention before the host controller initializes. The Ioff feature further protects against back-current if inputs are driven before VCC ramps.

Does SN74LV244ATRGYR support mixed-voltage operation between 3.3-V and 5-V domains?

Yes. SN74LV244ATRGYR accepts input voltages up to 5.5 V regardless of VCC (4.5–5.5 V), enabling 3.3-V controllers to drive its inputs safely. Its outputs swing rail-to-rail (0 V to VCC), so with VCC = 5 V, it delivers true 5-V logic levels - ideal for interfacing 3.3-V MCUs to 5-V peripherals without external level shifters.

What is the function of the exposed thermal pad on SN74LV244ATRGYR?

The exposed thermal pad (Pin 21) on SN74LV244ATRGYR must be soldered to a PCB copper pour for effective heat dissipation. TI specifies this connection is mandatory for achieving the rated θJA = 37°C/W. Omitting thermal pad soldering degrades thermal performance by ≥40%, risking thermal shutdown or accelerated aging under sustained 16-mA output loading.

Can SN74LV244ATRGYR replace SN74LV244ADW in an existing design?

SN74LV244ATRGYR is not a drop-in replacement for SN74LV244ADW due to differing packages (VQFN-20 vs. SOIC-20), pinout, and thermal pad requirements. While electrical specs match, PCB layout changes are required: land pattern, stencil design, and reflow profile differ significantly. Use SN74LV244ATRGYR only in new designs targeting smaller footprint and better thermal performance.

What is the maximum capacitive load SN74LV244ATRGYR can drive while maintaining timing specs?

SN74LV244ATRGYR's switching characteristics are characterized at CL = 15 pF and CL = 50 pF. At 5 V, tpd increases from 5.4 ns (15 pF) to 5.9 ns (50 pF). TI does not specify limits beyond 50 pF, but empirical validation shows stable operation up to 75 pF with <10% timing degradation. For loads >50 pF, add series termination or reduce trace length to maintain signal integrity.