Texas Instruments SN74LVC126ARGYR

Overview

SN74LVC126ARGYR from Texas Instruments is a quadruple 3-state bus buffer gate operating from 1.65 V to 3.6 V, featuring 5.5-V-tolerant inputs, 4.7 ns maximum propagation delay at 3.3 V, and –40°C to +125°C temperature range. It serves as a level-translating buffer in mixed-voltage digital interfaces such as MCU-to-peripheral data buses in consumer audio and display systems.

For engineers reviewing the SN74LVC126ARGYR datasheet, SN74LVC126ARGYR pinout, SN74LVC126ARGYR application, or SN74LVC126ARGYR equivalent, key selection criteria include 3-state output control timing (ten/tdis), input overvoltage tolerance, thermal performance in VQFN-14 (RGY), and compatibility with 1.8 V/2.5 V/3.3 V logic families in high-density PCB layouts.

Technical Context

The SN74LVC126ARGYR implements four independent non-inverting buffers, each with dedicated active-low output-enable (OE) control. Its CMOS design supports rail-to-rail output swing (VOL ≤ 0.3 V, VOH ≥ VCC – 0.3 V at 125°C) and exhibits balanced rise/fall times under 5 ns at 3.3 V.

Input voltage tolerance up to 5.5 V enables use as a down-translator from 5 V logic to 3.3 V or 1.8 V domains without external level-shifting circuitry. The device requires pulldown biasing of OE pins during power sequencing to guarantee high-impedance state at startup.

Key Specifications

Pinout & Package

VQFN-14 (RGY) package: 3.50 mm × 3.50 mm body, 0.5 mm pitch, exposed thermal pad connected to GND for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC126ARGYR, SN74LVC125ARGYR demands OE signal inversion but offers identical performance, while 74LVC126PWRE4 trades thermal efficiency and size for ease of assembly - both require validation of timing margins under worst-case junction temperature.

Availability

SN74LVC126ARGYR is available at Aetrix Electronics and suitable for audio docks, solid-state drives, HDTV subsystems, and industrial PLC I/O expansion requiring stable component supply across extended temperature ranges.

Supply support for SN74LVC126ARGYR 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 and embedded processing technologies, with decades of expertise in logic IC design and automotive-grade qualification.

The SN74LVC126ARGYR belongs to TI's LVC (Low-Voltage CMOS) logic family, engineered for low-power, high-speed interfacing in mixed-voltage systems - particularly targeting consumer electronics, storage, and industrial control applications.

FAQ

What is the recommended pull-down resistor value for OE pins on SN74LVC126ARGYR?

The minimum pull-down resistor value for OE pins on SN74LVC126ARGYR depends on the current-sourcing capability of the driver controlling OE. For typical 3.3 V GPIOs with 4 mA sink capability, a 10 kΩ resistor ensures reliable low-state assertion during power-up while limiting static current to <0.33 mA. TI recommends verifying against actual driver specs in the system design.

Can SN74LVC126ARGYR interface a 5 V microcontroller with a 1.8 V FPGA?

Yes, SN74LVC126ARGYR can safely interface a 5 V microcontroller with a 1.8 V FPGA: its inputs tolerate up to 5.5 V regardless of VCC, and its outputs swing rail-to-rail between GND and VCC (1.8 V). When powered at 1.8 V, it translates 5 V inputs to 1.8 V-compatible outputs without external components.

Does SN74LVC126ARGYR require external bypass capacitors, and if so, what value?

Yes, SN74LVC126ARGYR requires a 0.1 µF ceramic bypass capacitor placed as close as possible to the VCC pin (Pin 14) and GND (Pin 7). This minimizes supply noise and prevents voltage droop during fast output transitions. For systems with multiple VCC connections or high-frequency noise, paralleling with a 1 µF capacitor is recommended.

What is the maximum clock frequency supported by SN74LVC126ARGYR in a data bus application?

SN74LVC126ARGYR supports data bus frequencies up to 100 MHz, based on its 4.7 ns maximum propagation delay at 3.3 V and sub-6 ns enable/disable timing. At 1.8 V, tpd increases to 9.3 ns (max), limiting reliable operation to ~50 MHz; timing margin verification per application conditions is essential.

How is thermal management handled in the RGY package of SN74LVC126ARGYR?

The RGY (VQFN-14) package of SN74LVC126ARGYR features an exposed thermal pad that must be soldered to a PCB ground plane using ≥4 thermal vias. This achieves a junction-to-board thermal resistance of 66.7°C/W, enabling continuous operation at full drive strength within the –40°C to +125°C range without derating.