Texas Instruments SN74AUC125RGYR

Overview

SN74AUC125RGYR from Texas Instruments is a quadruple bus buffer gate with 3-state outputs, designed for 1.6-V to 1.95-V V_CC operation and 3.6-V I/O tolerant signaling. It delivers sub-2.1 ns propagation delay at 1.8 V, ±8-mA output drive, and supports partial-power-down via I_off. It is used in low-voltage data bus isolation and level translation between 1.8-V logic domains in portable computing and high-speed interface subsystems.

For engineers reviewing the SN74AUC125RGYR datasheet, SN74AUC125RGYR pinout, SN74AUC125RGYR application, or SN74AUC125RGYR equivalent, key selection criteria include 1.8-V optimized timing, 3-state bus contention control, I_off-enabled power sequencing, and VQFN-14 thermal pad compatibility in space-constrained PCB layouts.

Technical Context

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

It operates across 0.8-V to 2.7-V supply range but is fully characterized and optimized for 1.6–1.95-V operation, with guaranteed 2.1-ns t_pd at 1.8 V and CL = 15 pF. The I_off circuitry actively disables outputs during power-down, blocking reverse current flow even when V_CC = 0 V and I/O pins are driven externally.

Key Specifications

Pinout & Package

VQFN-14 (RGY) package: 3.5 mm × 3.5 mm body, 0.5-mm lead pitch, 1-mm max height, thermally enhanced with exposed die-pad soldered to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC125APWR and SN74AUP1T125DBVR, the SN74AUC125RGYR uniquely balances 1.8-V speed (2.1 ns), quad-channel density, and I_off-enabled power management - making it optimal for compact, high-throughput 1.8-V bus architectures where timing, integration, and power sequencing coexist as hard constraints.

Availability

SN74AUC125RGYR is available at Aetrix Electronics and suitable for mobile baseband interfaces, FPGA I/O expansion, low-power SSD controller buses, and industrial sensor hub aggregation requiring stable component supply and long-term production continuity.

Supply support for SN74AUC125RGYR 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 with emphasis on reliability, energy efficiency, and system-level integration.

The SN74AUC125RGYR belongs to TI's AUC logic family, engineered specifically for ultra-high-speed, low-voltage operation in portable and high-density digital systems where 1.8-V timing and I/O tolerance are mandatory.

FAQ

What is the minimum supply voltage for reliable operation of the SN74AUC125RGYR?

The SN74AUC125RGYR is fully specified down to 0.8 V, but its optimized performance window is 1.6–1.95 V. At 0.8 V, propagation delay increases to 5.8 ns and output drive drops significantly; for production designs targeting sub-2.1 ns timing, V_CC must be maintained ≥1.6 V per TI SCES508A specifications.

Does the SN74AUC125RGYR support hot insertion or live bus swapping?

Yes - the SN74AUC125RGYR supports live insertion via its I_off circuitry, which disables outputs and blocks reverse current when V_CC = 0 V. This allows safe connection/disconnection while other system rails remain active, provided OE pins are held high during insertion to maintain high-impedance state.

How should the thermal pad on the SN74AUC125RGYR VQFN package be handled in PCB layout?

The exposed thermal pad of the SN74AUC125RGYR must be soldered to a solid PCB ground plane using at least 8 thermal vias (0.3-mm diameter, spaced ≤1 mm apart). TI recommends 80% solder paste coverage on the pad and a non-solder-mask-defined (NSMD) land pattern per SLUA271 guidelines to ensure mechanical stability and thermal performance.

Can the SN74AUC125RGYR be used to translate signals from 3.3-V to 1.8-V logic levels?

No - the SN74AUC125RGYR is not a level translator. Its inputs accept up to 3.6-V signals (3.3-V compatible), but outputs swing only between GND and V_CC (1.8 V). To drive a true 1.8-V load from a 3.3-V source, an external pull-down or dedicated level shifter is required; the SN74AUC125RGYR provides voltage-tolerant input reception only.

What is the recommended pull-up resistor value for OE pins on the SN74AUC125RGYR during power-up?

Texas Instruments specifies that OE pins should be tied to V_CC through a pull-up resistor sized to sink ≤10 µA (max I_I). For V_CC = 1.8 V, a 180-kΩ resistor ensures sufficient margin; values between 47 kΩ and 220 kΩ are commonly used to balance noise immunity and current draw in production designs using the SN74AUC125RGYR.