Texas Instruments SN74AUC244RGYR

Overview

SN74AUC244RGYR from Texas Instruments is an octal noninverting buffer/driver with 3-state outputs, designed for 1.65-V to 1.95-V V_CC operation and 3.6-V I/O tolerant signaling. It features ±8-mA output drive at 1.8 V, 1.9-ns max propagation delay, 20-µA max ICC, and I_off support for partial-power-down mode - deployed in low-voltage FPGA I/O bridging and high-speed memory interface buffering.

For engineers reviewing the SN74AUC244RGYR datasheet, SN74AUC244RGYR pinout, SN74AUC244RGYR application, or SN74AUC244RGYR equivalent, key selection criteria include sub-2-ns timing at 1.8 V, 3.6-V I/O tolerance for mixed-voltage domain interfacing, I_off-enabled power sequencing compliance, and QFN-20 (RGY) thermal pad layout requirements.

Technical Context

The SN74AUC244RGYR implements two independent 4-bit noninverting buffers, each controlled by a dedicated output-enable (OE) input. Its logic operates across 0.8-V to 2.7-V V_CC, with guaranteed performance at 1.8 V ±0.15 V and CL = 15 pF.

It uses advanced AUC logic family architecture enabling sub-1-V operation, rail-to-rail output swing, and robust ESD protection (2000-V HBM, 200-V MM, 1000-V CDM). The I_off circuitry actively disables outputs during power-down to prevent backflow current.

Key Specifications

Pinout & Package

VQFN-20 (RGY) package with 3.5 mm × 4.5 mm body, 0.5-mm lead pitch, and exposed thermal pad (Pin 21) requiring solder connection to PCB ground plane for thermal and mechanical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWR and 74AUP2G126DCUR, the SN74AUC244RGYR uniquely delivers sub-2-ns timing at 1.8 V with full 3.6-V I/O tolerance and I_off - making it the only option qualified for high-speed, mixed-supply, hot-pluggable bus architectures.

Availability

SN74AUC244RGYR is available at Aetrix Electronics and suitable for FPGA I/O expansion, low-voltage memory interface, and industrial PLC backplane buffering requiring stable component supply across extended temperature ranges (–40°C to 85°C).

Supply support for SN74AUC244RGYR 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 SN74AUC244RGYR belongs to TI's ultra-low-voltage AUC logic family, engineered specifically for high-speed, low-power signal routing in battery-powered and thermally constrained portable and embedded systems.

FAQ

What is the minimum V_CC required for functional operation of the SN74AUC244RGYR?

The SN74AUC244RGYR is fully operational down to 0.8 V V_CC, with guaranteed timing and drive performance specified from 1.65 V to 1.95 V. At 0.8 V, it maintains logic functionality but with relaxed timing (tpd up to 6.5 ns) and reduced output drive - making SN74AUC244RGYR suitable for ultra-low-power wake-up circuits and energy-harvesting systems where nominal 1.8-V rails may dip transiently.

Does the SN74AUC244RGYR support hot-swap or live-insertion in powered-backplane systems?

Yes, the SN74AUC244RGYR supports hot-swap via its I_off circuitry, which disables outputs and limits leakage to ±10 µA when V_CC = 0 V and inputs/outputs are biased up to 2.7 V. This prevents damaging current backflow during insertion into a live 3.3-V backplane - a key requirement validated per JESD78 Class II latch-up testing and confirmed in TI's SCES432 datasheet section "Ioff Supports Partial-Power-Down Mode Operation" for SN74AUC244RGYR.

How should the exposed thermal pad (Pin 21) of the SN74AUC244RGYR be connected on the PCB?

The exposed thermal pad (Pin 21) of the SN74AUC244RGYR must be soldered directly to a solid copper ground plane on the PCB using a minimum of 4–6 thermal vias (0.3-mm diameter, spaced ≤1 mm apart) beneath the pad. TI's SLUA271 application note specifies this connection as mandatory for achieving the rated θ_JA of 37°C/W and preventing thermal shutdown under sustained ±8-mA output loading - failure to connect Pin 21 degrades thermal performance by >40% and risks long-term reliability failure in SN74AUC244RGYR deployments.

Can the SN74AUC244RGYR interface directly with 3.3-V CMOS logic without level-shifting components?

Yes, the SN74AUC244RGYR supports 3.6-V I/O tolerance, meaning its inputs and outputs accept and drive signals from –0.5 V to 3.6 V regardless of V_CC level - verified across absolute maximum ratings and recommended operating conditions in SCES432. When V_CC = 1.8 V, SN74AUC244RGYR reliably receives 3.3-V logic highs and drives 3.3-V loads, eliminating external level shifters in mixed-voltage systems such as 1.8-V SoCs interfacing to 3.3-V peripheral buses.

What is the recommended pull-up resistor value for OE pins on the SN74AUC244RGYR during power-up?

Texas Instruments recommends tying OE pins of the SN74AUC244RGYR to V_CC via a pull-up resistor with minimum value determined by the driver's current-sinking capability - typically 10 kΩ for standard 1.8-V operation. This ensures outputs remain in high-impedance state during power ramp-up, preventing bus contention. The exact value depends on system noise margin and rise time requirements, but 10 kΩ is validated in TI's application guidance for SN74AUC244RGYR and balances leakage current (<0.2 µA) against transient immunity.