Texas Instruments SN74LVC1G125DSFR

Overview

SN74LVC1G125 from Texas Instruments is a single 3-state bus buffer gate used for signal isolation and bus contention control in low-voltage digital systems. It features true noninverting logic, 3.3V/5V supply compatibility (1.65–5.5V), ±24mA output drive at 3.3V, 3.7ns max propagation delay, and Ioff support for live insertion. It is commonly deployed in high-speed data acquisition interfaces and SSD internal signal routing.

For engineers reviewing the SN74LVC1G125 datasheet, SN74LVC1G125 pinout, SN74LVC1G125 application, or SN74LVC1G125 equivalent, key selection considerations include its ultra-small X2SON-5 (DPW) package, over-voltage tolerant inputs up to 5.5V, 3-state enable timing (ten/tdis), thermal performance in industrial temperature range (–40°C to 125°C), and compatibility with mixed-voltage LVC logic families.

Technical Context

The SN74LVC1G125 implements a CMOS-based noninverting buffer with active-low 3-state enable (OE). Its output transitions between driving high, driving low, and high-impedance states based solely on OE and A input logic levels - no internal latching or clocking. The device uses balanced CMOS output stages enabling symmetrical sourcing/sinking capability.

It incorporates Ioff circuitry that disables all outputs when VCC = 0V, preventing back-drive current during partial power-down. Inputs tolerate voltages up to 5.5V independent of VCC, enabling level translation from 5V-tolerant sources into 3.3V or 1.8V domains without external components.

Key Specifications

Pinout & Package

SN74LVC1G125DSFR is packaged in the DPW (X2SON-5) ultra-small outline package measuring 0.8mm × 0.8mm with 0.5mm pitch. This 5-pin, no-lead package features wettable flanks for automated optical inspection and is optimized for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G126DSFR, SN74LVC1G125DSFR provides noninverting behavior essential for transparent data pass-through; compared with 74LVC1G125GW,125, it delivers 60% smaller PCB area and improved thermal resistance (RθJA = 340°C/W vs. 371°C/W), critical for thermally constrained SSD and radar modules.

Availability

SN74LVC1G125DSFR is available at Aetrix Electronics and suitable for high-speed data acquisition, SSD internal routing, and video broadcasting scalable platforms requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVC1G125DSFR 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 decades of expertise in high-reliability interface ICs and automotive-grade qualification.

The SN74LVC1G125 belongs to TI's LVC logic family designed for low-voltage, high-speed, mixed-signal interfacing in space- and power-constrained applications including storage, test equipment, and defense electronics.

FAQ

What is the recommended pullup resistor value for OE on SN74LVC1G125DSFR?

The OE pin should be tied to VCC through a pullup resistor to ensure high-impedance state during power-up. Based on the device's maximum sink current (24mA at 3.3V) and typical system noise margins, a 10kΩ resistor is recommended. This value balances fast enable timing, low static current draw (<0.33mA), and robust noise immunity for SN74LVC1G125DSFR in industrial environments.

Can SN74LVC1G125DSFR interface a 5V microcontroller with a 1.8V FPGA?

Yes. SN74LVC1G125DSFR accepts input voltages up to 5.5V regardless of VCC, so its A and OE pins can safely connect to 5V logic. When powered at 1.8V, it outputs valid 1.8V logic levels (VOH ≥ 1.62V, VOL ≤ 0.2V) compatible with FPGA I/O banks. This makes SN74LVC1G125DSFR suitable for unidirectional 5V-to-1.8V level translation without external components.

Does SN74LVC1G125DSFR support hot-swap or live-insertion applications?

Yes. SN74LVC1G125DSFR includes Ioff circuitry that disables all outputs when VCC = 0V, limiting leakage current to ±10μA. This prevents back-driving of powered circuitry during insertion into live backplanes or modular systems. Combined with its –40°C to 125°C rating and JESD78 Class II latch-up immunity (>100mA), SN74LVC1G125DSFR is qualified for hot-swap designs in telecom and military hardware.

What is the maximum capacitive load SN74LVC1G125DSFR can drive while maintaining 3.7ns tpd?

The 3.7ns maximum propagation delay for SN74LVC1G125DSFR is specified at CL = 15pF. Driving loads >15pF increases tpd nonlinearly - e.g., at CL = 30pF, tpd rises to 4.5ns (–40°C to 85°C). For designs requiring strict 3.7ns timing, keep total load capacitance ≤15pF via short traces and minimal stubs. For heavier loads, add a series damping resistor near Y to suppress ringing without violating SN74LVC1G125DSFR's 24mA drive limit.

How does SN74LVC1G125DSFR handle unused inputs?

All unused inputs on SN74LVC1G125DSFR - including A and OE - must be terminated to a valid logic level (VCC or GND) to prevent floating nodes, which cause excessive ICC, oscillation, or ESD susceptibility. TI recommends 10kΩ pullup/pulldown resistors. Leaving OE unconnected risks undefined output states during power transitions; leaving A floating violates CMOS input requirements and may increase power consumption. This applies strictly to SN74LVC1G125DSFR and all LVC-family devices.