Texas Instruments SN74AUC125RGYRG4

Overview

SN74AUC125RGYRG4 from Texas Instruments is a quadruple bus buffer gate with 3-state outputs, designed for low-voltage operation (1.6–1.95 V V_CC), delivering 2.1 ns max propagation delay at 1.8 V, ±8-mA output drive, and I_off-enabled partial-power-down support-used in high-speed memory address/data bus isolation in portable SSD controllers.

For engineers reviewing the SN74AUC125RGYRG4 datasheet, SN74AUC125RGYRG4 pinout, SN74AUC125RGYRG4 application, or SN74AUC125RGYRG4 equivalent, key selection criteria include sub-2-ns timing at 1.8 V, 3.6-V I/O tolerance for mixed-mode interfacing, I_off current limiting, and VQFN-14 thermal pad requirements for thermal management in space-constrained embedded systems.

Technical Context

This device implements four independent noninverting buffers, each with dedicated 3-state output-enable (OE) control. All outputs enter high-impedance state when OE is high, enabling bidirectional bus sharing without external direction control logic.

It features sub-1-V operability, JESD 78 Class II latch-up immunity (>100 mA), and ESD protection per JESD 22 (2000-V HBM, 200-V MM, 1500-V CDM), making it suitable for hot-plug-capable interfaces in battery-powered edge devices.

Key Specifications

Pinout & Package

VQFN-14 (RGY) package: 3.5 mm × 3.5 mm body, 0.5 mm pitch, 1 mm max height, exposed thermal pad requiring PCB solder connection for thermal and mechanical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC125APW and 74AUP1G125DBV, SN74AUC125RGYRG4 uniquely combines quad-channel integration, sub-2-ns timing at 1.8 V, and I_off-enabled power sequencing-making it optimal for compact, high-speed, mixed-rail embedded systems requiring deterministic bus isolation.

Availability

SN74AUC125RGYRG4 is available at Aetrix Electronics and suitable for mobile SSD controllers, FPGA I/O expansion, USB-C alternate mode switching, and industrial PLC digital input modules requiring stable component supply across extended product lifecycles.

Supply support for SN74AUC125RGYRG4 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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and consumer markets.

The SN74AUC logic family targets ultra-low-voltage, high-speed digital interfacing-designed specifically for 1.6–1.95-V operation in portable, battery-powered, and thermally constrained systems where timing, power, and voltage compatibility are critical.

FAQ

What is the maximum operating frequency supported by SN74AUC125RGYRG4?

The SN74AUC125RGYRG4 does not specify a maximum clock frequency directly, but its 2.1 ns maximum propagation delay at 1.8 V implies reliable operation up to approximately 400 MHz in well-terminated, low-capacitance bus environments. Actual usable frequency depends on load capacitance, signal integrity, and board layout-TI recommends verifying timing margins using the switching characteristics table in the SCES508A datasheet for SN74AUC125RGYRG4.

Does SN74AUC125RGYRG4 support hot-plug operation?

Yes, SN74AUC125RGYRG4 supports hot-plug operation via its I_off feature, which limits current to ±10 µA when V_CC = 0 V and inputs/outputs are biased to 2.7 V. This prevents damaging backflow current during live insertion or removal in modular systems like PCIe add-in cards or USB-C docking stations-provided OE pins are held high during power-off states to maintain high-impedance outputs.

What is the recommended decoupling strategy for SN74AUC125RGYRG4?

TI specifies a 0.1-µF ceramic capacitor placed within 3 mm of the V_CC pin (Pin 8) and GND (Pin 7) for SN74AUC125RGYRG4. For systems with multiple devices or high di/dt loads, add a bulk 4.7-µF tantalum or polymer capacitor near the power entry point. The exposed thermal pad must be soldered to a solid ground plane to serve as both thermal path and low-inductance return for high-frequency switching currents.

Can SN74AUC125RGYRG4 interface directly with 3.3-V logic?

Yes, SN74AUC125RGYRG4 accepts input voltages up to 3.6 V and tolerates 3.3-V signals on all A and OE inputs while operating from a 1.8-V V_CC, making it suitable for direct interfacing with 3.3-V peripherals without level shifters. However, its outputs swing only from GND to V_CC (1.8 V), so driving 3.3-V CMOS inputs requires verification of VIH(min) compatibility-typically satisfied for 3.3-V LVTTL or LVCMOS with VIH ≥ 2.0 V.

Is the thermal pad on SN74AUC125RGYRG4 electrically connected internally?

No, the exposed thermal pad on SN74AUC125RGYRG4 is not electrically connected to any internal node-it is a mechanical and thermal enhancement feature only. TI documentation explicitly states the pad must be soldered to a PCB ground plane for thermal performance and mechanical reliability, but no electrical connection is required or recommended. Connecting it to GND improves heat dissipation and reduces θ_JA from 47°C/W to lower values depending on copper area and via count.