Texas Instruments SN74AUCH244RGYR

Overview

SN74AUCH244RGYR from Texas Instruments is an octal noninverting buffer/driver IC designed for low-voltage, high-speed bus interface applications. It features two independent 4-bit sections with separate output-enable (OE) controls, operates from 0.8 V to 2.7 V (optimized at 1.8 V), delivers ±8-mA drive strength, achieves 1.9-ns max propagation delay at 1.8 V, and includes bus-hold circuitry to eliminate external pull resistors - used in portable memory interfaces and low-power FPGA I/O bridging.

For engineers reviewing the SN74AUCH244RGYR datasheet, SN74AUCH244RGYR pinout, SN74AUCH244RGYR application, or SN74AUCH244RGYR equivalent, key selection criteria include its 1.8-V optimized timing performance, Ioff-enabled partial-power-down capability, 3.6-V I/O tolerance for mixed-mode signal interfacing, and VQFN-20 (RGY) package compatibility with space-constrained PCB layouts.

Technical Context

This device implements dual 4-bit noninverting buffers with active-low OE control per section, enabling independent enable/disable of each 4-bit group. Its bus-hold inputs maintain valid logic states without external biasing, and the Ioff circuitry actively disables outputs during power-down to prevent back-current flow.

The SN74AUCH244RGYR uses a CMOS process optimized for sub-1.8-V operation, supports 3.6-V tolerant I/Os across the full VCC range (0.8–2.7 V), and meets JESD 78 Class II latch-up immunity (>100 mA) and JESD 22 ESD ratings (2000-V HBM, 200-V MM, 1000-V CDM).

Key Specifications

Pinout & Package

VQFN-20 (RGY) package: 3.5 mm × 4.5 mm, 0.5-mm pitch, 1-mm max height, exposed thermal pad (Pin 21) requiring PCB solder connection 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 SN74AUCH244RGYR, SN74LVC244APWR lacks critical low-voltage features (sub-1-V operation, Ioff, bus-hold), while SN74AUC244RGYR is a functionally identical variant confirmed by TI as pin-and-function compatible - making it the only true drop-in alternative.

Availability

SN74AUCH244RGYR is available at Aetrix Electronics and suitable for portable computing interfaces, industrial PLC I/O expansion, and battery-powered sensor node designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74AUCH244RGYR 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 logic solutions, with over 90 years of innovation in industrial, automotive, and consumer electronics.

The SN74AUCH244RGYR belongs to TI's AUCH logic family - engineered specifically for ultra-low-voltage, high-speed digital interfacing in space- and power-constrained applications such as mobile SoCs and IoT edge nodes.

FAQ

What is the minimum operating voltage for SN74AUCH244RGYR?

The SN74AUCH244RGYR operates down to 0.8 V VCC, with guaranteed functionality across the full 0.8–2.7 V range. At 0.8 V, it maintains valid logic thresholds and specified output drive (±0.7 mA), enabling use in emerging sub-1-V microcontroller domains where traditional logic families fail. This capability is explicitly validated in the recommended operating conditions table of the SCES433 datasheet.

Does SN74AUCH244RGYR support hot-swap or partial-power-down operation?

Yes, SN74AUCH244RGYR supports partial-power-down via its Ioff circuitry, which limits off-state current to ±10 µA when VCC = 0 V and any I/O is biased. This prevents damaging back-current flow in modular systems like PCIe cards or field-replaceable units. The feature is tested per JESD 78 Class II and documented in the absolute maximum ratings and electrical characteristics sections of the datasheet.

How does the bus-hold function work on SN74AUCH244RGYR inputs?

The bus-hold circuitry on SN74AUCH244RGYR inputs actively maintains the last-valid logic state when inputs float, using internal feedback transistors with sustaining currents (IBHL/IBHH) ranging from ±10 µA to ±275 µA depending on VCC. It eliminates need for external pull resistors - but using external bias with bus-hold is discouraged as it may cause contention or increased power draw, per the functional description in the datasheet.

What is the thermal pad (Pin 21) requirement for SN74AUCH244RGYR?

The exposed thermal pad (Pin 21) of SN74AUCH244RGYR must be soldered to a dedicated PCB copper pour connected to GND for mechanical stability and thermal dissipation. TI's SLUA271 application note specifies minimum solder coverage (78% of pad area) and recommends via-in-pad design with filled/plugged vias. Failure to connect this pad risks thermal overstress and solder joint reliability failure under continuous 8-mA output loading.

Is SN74AUCH244RGYR pin-compatible with other 20-pin VQFN octal buffers?

SN74AUCH244RGYR has a unique pinout defined in the RGY package drawing (SCES433, page 1), with OE controls on Pins 9 and 16, VCC on Pin 10, and GND on Pin 11. It is not pin-compatible with SN74LVC244APWR (TSSOP-20) or SN74AUC244RGYR (same RGY pinout but different marking). Always verify against the official TI RGY mechanical drawing - no generic "20-pin VQFN" assumption is valid.