Texas Instruments SN74LVCH244ARGYR

Overview

SN74LVCH244ARGYR from Texas Instruments is an octal buffer/line driver with 3-state outputs, designed for 1.65 V to 3.6 V operation. It features bus-hold circuitry on all data inputs, I_off support for partial-power-down mode, and mixed-mode signal compatibility (5-V input tolerance with 3.3-V V_CC). It is used in bidirectional data bus interfacing between 3.3-V and 5-V logic domains in industrial control and embedded communications systems.

For engineers reviewing the SN74LVCH244ARGYR datasheet, SN74LVCH244ARGYR pinout, SN74LVCH244ARGYR application, or SN74LVCH244ARGYR equivalent, key selection criteria include its 20-pin VQFN (RGY) package, 5.9 ns max propagation delay at 3.3 V, ±24 mA output drive capability, bus-hold functionality eliminating external resistors, and I_off protection during power sequencing.

Technical Context

The SN74LVCH244ARGYR implements two independent 4-bit noninverting buffers, each with dedicated output-enable (OE) control. Its bus-hold circuitry actively maintains valid logic states on undriven A-inputs without external pullup/pulldown resistors, reducing BOM count and layout complexity.

It supports mixed-voltage translation: A-inputs tolerate up to 5.5 V regardless of V_CC, enabling direct connection to 5-V sources while operating from 1.65–3.6 V. The I_off feature disables outputs and blocks current backflow when V_CC = 0, ensuring safe partial-power-down operation in hot-swap or multi-rail systems.

Key Specifications

Pinout & Package

VQFN-20 (RGY) package: 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 thermal performance and mechanical reliability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVCH244ARGYR, SN74LVC244APWR lacks bus-hold and requires external resistors, increasing layout complexity, while SN74AVC244PWR offers faster timing but sacrifices 5-V input compatibility-making SN74LVCH244ARGYR the optimal choice for mixed-voltage industrial and automotive bus interfacing where robustness and design simplicity are prioritized.

Availability

SN74LVCH244ARGYR is available at Aetrix Electronics and suitable for industrial PLC backplanes, FPGA I/O expansion hubs, automotive body control modules, and medical diagnostic equipment requiring stable component supply and long-term manufacturability.

Supply support for SN74LVCH244ARGYR 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 SN74LVCH244ARGYR belongs to TI's LVCH logic family, engineered for robust mixed-voltage interfacing in harsh environments-designed specifically to simplify voltage translation, reduce external components, and ensure reliable operation across wide temperature and supply ranges.

FAQ

What is the maximum input voltage rating for SN74LVCH244ARGYR?

The SN74LVCH244ARGYR supports input voltages from 0 V to 5.5 V across its entire operating V_CC range (1.65–3.6 V). This 5-V tolerance allows direct connection to legacy 5-V logic families without external level-shifting circuitry, making SN74LVCH244ARGYR ideal for upgrading systems while maintaining backward compatibility.

Does SN74LVCH244ARGYR require external pullup or pulldown resistors on its inputs?

No. SN74LVCH244ARGYR integrates active bus-hold circuitry on all eight A-inputs, which maintains valid logic states on undriven or floating inputs. This eliminates the need for external pullup or pulldown resistors, reducing BOM cost and PCB real estate-confirmed in the device's functional description and electrical characteristics table.

What is the purpose of the exposed thermal pad (Pin 21) on the SN74LVCH244ARGYR RGY package?

The exposed thermal pad (Pin 21) on SN74LVCH244ARGYR serves dual functions: thermal dissipation (reducing θ_JA to 37°C/W) and mechanical anchoring. TI's packaging documentation mandates soldering this pad directly to the PCB ground plane to ensure reliable thermal performance and prevent solder joint fatigue under thermal cycling-failure to do so degrades both reliability and timing margins.

How does the I_off feature of SN74LVCH244ARGYR protect the system during power-down?

The I_off feature in SN74LVCH244ARGYR disables all outputs and blocks current flow when V_CC = 0 V, limiting leakage to ±10 µA. This prevents damaging back-current from live signal lines into a powered-down device-a critical safeguard during hot-swap events or multi-rail power sequencing in industrial and automotive systems using SN74LVCH244ARGYR.

Can SN74LVCH244ARGYR be used as a direct replacement for SN74LVC244A in existing designs?

SN74LVCH244ARGYR is pin-compatible with SN74LVC244A in the RGY package and shares identical pinout and DC specifications, but adds bus-hold and enhanced I_off. While functionally superior, designers must verify that bus-hold behavior aligns with system timing-especially in edge-sensitive applications-as it may alter input transition thresholds compared to the base LVC version.