Texas Instruments SN74LVCH244ARGYRG4

Overview

SN74LVCH244ARGYRG4 from Texas Instruments is an octal buffer/line driver with 3-state outputs, designed for 1.65-V to 3.6-V VCC operation. It features two independent 4-bit channels, bus-hold circuitry on all inputs, Ioff partial-power-down support, and mixed-mode 5-V input tolerance with 3.3-V supply-enabling use in level-translating interfaces between legacy 5-V and modern low-voltage logic systems.

For engineers reviewing the SN74LVCH244ARGYRG4 datasheet, SN74LVCH244ARGYRG4 pinout, SN74LVCH244ARGYRG4 application, or SN74LVCH244ARGYRG4 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 elimination of external pull resistors, and Ioff protection for hot-swap and power sequencing scenarios.

Technical Context

This device implements dual 4-bit noninverting buffers with independent 3-state control (1OE and 2OE), enabling selective channel isolation. Each buffer passes data from A-inputs to Y-outputs when OE is low; outputs enter high-impedance state when OE is high.

Bus-hold circuitry actively maintains valid logic levels on unused or floating inputs without external components, while Ioff limits current flow during partial power-down. Input voltage tolerance up to 5.5 V allows direct interfacing with 5-V TTL outputs even when VCC = 1.65 V–3.6 V.

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. RoHS-compliant, NIPDAU lead finish, MSL Level-2-260°C-1 year.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWR and SN74AVC244RHLR, the SN74LVCH244ARGYRG4 uniquely combines bus-hold, Ioff, and 5-V input tolerance in a compact VQFN package-making it optimal for robust, maintainable, mixed-voltage embedded interfaces where reliability and layout efficiency are prioritized.

Availability

SN74LVCH244ARGYRG4 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, and embedded test equipment requiring stable component supply and long-term lifecycle support.

Supply support for SN74LVCH244ARGYRG4 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 personal electronics markets.

The SN74LVCH244A product line delivers robust, low-voltage octal buffers with integrated bus-hold and Ioff for reliable signal conditioning in mixed-voltage and hot-swap-capable systems.

FAQ

What is the maximum operating temperature range for the SN74LVCH244ARGYRG4?

The SN74LVCH244ARGYRG4 is rated for operation from –40°C to +85°C ambient temperature. This industrial temperature range is confirmed in TI's official ordering information and package addendum documents, and applies specifically to the RGY package variant. The device's thermal performance is supported by a θJA of 37°C/W in the VQFN-20 package.

Does the SN74LVCH244ARGYRG4 require external pull-up or pull-down resistors on its inputs?

No, the SN74LVCH244ARGYRG4 does not require external pull-up or pull-down resistors on its inputs because it integrates active bus-hold circuitry on all eight A-inputs. This feature maintains valid logic states on undriven or floating inputs, eliminating BOM cost and board space overhead. Using external resistors with bus-hold enabled is explicitly discouraged in the datasheet.

Can the SN74LVCH244ARGYRG4 safely interface with 5-V logic outputs while powered from a 1.8-V supply?

Yes, the SN74LVCH244ARGYRG4 can safely accept 5-V logic-level inputs while operating from a 1.8-V VCC supply. Its input voltage range is specified as 0 V to 5.5 V across the full VCC range (1.65 V–3.6 V), enabling true mixed-mode translation. This capability is explicitly validated in the "Recommended Operating Conditions" table and functional description of the SN74LVCH244A family.

What is the purpose of the exposed thermal pad (Pin 21) on the SN74LVCH244ARGYRG4 package?

The exposed thermal pad (Pin 21) on the SN74LVCH244ARGYRG4 VQFN package must be soldered to the PCB ground plane to ensure adequate thermal dissipation and mechanical reliability. TI documentation specifies that this pad is electrically connected to GND internally and is required for meeting thermal impedance (θJA = 37°C/W) and long-term reliability targets. Omitting thermal pad connection risks overheating and premature failure under sustained load.

How does the Ioff feature of the SN74LVCH244ARGYRG4 protect the system during partial power-down?

The Ioff feature of the SN74LVCH244ARGYRG4 disables all output drivers and limits leakage current to ±10 µA when either VCC = 0 V or VI/VO = 5.5 V, preventing damaging back-current flow through the device during power sequencing or hot-swap events. This behavior is verified in the Electrical Characteristics table and is critical for maintaining signal integrity and protecting upstream drivers in multi-rail systems where subsystems power up/down asynchronously.