Texas Instruments SN74AUC1G125YZTR

Overview

SN74AUC1G125 from Texas Instruments is a single 3-state bus buffer gate optimized for 1.8-V operation, delivering ±8-mA output drive, 2.5-ns maximum propagation delay at 1.8 V/30 pF, 0.8–2.7-V operating voltage range, and over-voltage tolerant I/Os up to 3.6 V independent of VCC - used to enable/disable or redrive high-speed digital signals in compact portable and low-power logic interfaces.

For engineers reviewing the SN74AUC1G125 datasheet, SN74AUC1G125 pinout, SN74AUC1G125 application, or SN74AUC1G125 equivalent, key selection considerations include its NanoFree™ DSBGA-5 package footprint, Ioff partial-power-down capability, ULTTL output structure for 50–65-Ω transmission line driving without external termination, and guaranteed 250-MHz operation under 1.8-V/15-pF conditions.

Technical Context

The SN74AUC1G125 implements a noninverting 3-state buffer with active-low output-enable (OE) control, where Y = A when OE is low and Y = high-impedance when OE is high. Its ULTTL CMOS output stage provides balanced sourcing/sinking capability and dynamic impedance modulation during signal transitions to suppress ringing on controlled-impedance lines.

It supports partial power-down via Ioff circuitry that disables outputs and limits back-drive current when VCC = 0 V, and features standard CMOS inputs requiring termination to VCC or GND to prevent floating states - all while maintaining full functionality across 0.8–2.7-V supply range and tolerating 3.6-V I/O voltages regardless of VCC level.

Key Specifications

Pinout & Package

SN74AUC1G125 is available in three 5-pin packages: SOT-23 (DBV), SC70 (DCK), and NanoFree™ DSBGA (YZP). The YZP variant uses the die as the package (1.39 mm × 0.89 mm), enabling minimal PCB footprint and superior thermal performance (RθJB = 47.6°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G125DBVR and NC7SZ125P5X, the SN74AUC1G125 uniquely combines sub-1-V operation, 3.6-V I/O tolerance, Ioff, and NanoFree™ packaging - making it the only option for space-constrained, multi-rail, hot-pluggable applications demanding <2.5-ns timing.

Availability

SN74AUC1G125 is available at Aetrix Electronics and suitable for mobile baseband interfaces, wearable display links, sensor hub control paths, industrial I/O modules, and other applications requiring stable component supply with guaranteed long-term manufacturability.

Supply support for SN74AUC1G125 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 logic solutions, with over 90 years of innovation in high-reliability, energy-efficient IC design.

The SN74AUC1G125 belongs to TI's AUC sub-1-V logic family, engineered specifically for ultra-high-speed, low-power signal buffering in portable, wearables, and IoT edge devices operating at 0.8–2.7 V.

FAQ

What is the maximum operating frequency supported by the SN74AUC1G125?

The SN74AUC1G125 supports operation up to 250 MHz under optimal conditions (1.8 V, 15-pF load), verified by TI's characterization data. This corresponds to 500 Mbps data throughput in NRZ signaling. Real-world frequency depends on layout, load capacitance, and supply stability - with 2.5-ns propagation delay enabling reliable use in ≥400-Mbps serial links when combined with proper transmission line design.

Does the SN74AUC1G125 require external pull-up or pull-down resistors on unused pins?

Yes - all unused inputs (A and OE) of the SN74AUC1G125 must be terminated to VCC or GND to prevent floating states that cause excessive power consumption or oscillation. TI recommends a 10-kΩ resistor for OE to ensure predictable high-impedance behavior during power-up. The output Y should never be externally pulled unless required by downstream loading, as its ULTTL structure is designed for direct transmission line driving.

Can the SN74AUC1G125 safely interface between a 1.8-V microcontroller and a 3.3-V peripheral?

Yes - the SN74AUC1G125 supports 3.6-V I/O tolerance independent of VCC, allowing its inputs and outputs to accept or drive 3.3-V signals while powered from 1.8 V. This eliminates external level shifters in mixed-voltage systems. However, output voltage swing remains limited to 0–1.8 V when VCC = 1.8 V, so the 3.3-V peripheral must recognize 1.8-V logic high as valid - confirmed by TI's VIH specification (0.65 × VCC = 1.17 V min at 1.8 V).

What is the purpose of the Ioff feature in the SN74AUC1G125?

The Ioff feature in the SN74AUC1G125 disables all outputs and limits leakage current to ±10 µA when VCC = 0 V, preventing damaging back-current flow from live I/Os into a powered-down device. This is essential for hot-swap capability, partial power-down modes, and safe power sequencing in multi-rail systems - a capability not present in standard LVC or LV families.

Which package variant of the SN74AUC1G125 offers the smallest PCB footprint?

The YZP (DSBGA-5) package of the SN74AUC1G125 provides the smallest PCB footprint at 1.39 mm × 0.89 mm - enabled by Texas Instruments' NanoFree™ technology, which uses the silicon die itself as the package. This is 35% smaller than the SC70-5 (2.0 × 1.25 mm) and 52% smaller than the SOT-23-5 (2.9 × 1.6 mm), making it ideal for ultra-compact wearables and advanced mobile modules where board area is constrained.