Texas Instruments SN74LVC2G125DCUR

Overview

SN74LVC2G125 from Texas Instruments is a dual 3-state bus buffer gate IC designed for 1.65-V to 5.5-V operation, featuring two independent noninverting buffers with active-low output-enable controls (1OE, 2OE), ±24-mA drive at 3.3 V, 4.3-ns max propagation delay, and Ioff support for live insertion in partial-power-down systems. It serves as a level-translating signal isolator in high-speed digital interconnects between mixed-voltage domains.

For engineers reviewing the SN74LVC2G125 datasheet, SN74LVC2G125 pinout, SN74LVC2G125 application, or SN74LVC2G125 equivalent, key selection criteria include 3-state timing behavior, overvoltage-tolerant inputs (up to 5.5 V), thermal performance in VSSOP packaging, and compatibility with 1.8-V/2.5-V/3.3-V/5-V logic families in space-constrained PCB layouts.

Technical Context

The SN74LVC2G125 implements dual independent noninverting buffer functions (Y = A) with separate active-low output-enable inputs per channel. Each buffer supports rail-to-rail CMOS-compatible outputs and exhibits balanced push-pull drive capability-enabling fast edge rates into light loads while requiring careful routing to suppress ringing.

Its Ioff circuitry ensures high-impedance isolation during power-off conditions, preventing back-drive current flow. Inputs tolerate up to 5.5 V regardless of VCC level (1.65–5.5 V), enabling down-translation from higher-voltage sources to lower-supply logic domains without external level shifters.

Key Specifications

Pinout & Package

VSSOP-8 (DCUR) package: 2.30 mm × 2.00 mm body size, 0.5-mm lead pitch, exposed pad not present, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual 3-state buffer applications.

Compared with SN74LVC2G125, SN74LVC2G126DCUR offers identical timing and drive but inverted logic, while 74LVC2G125GW,125 sacrifices independent enable control for smaller footprint and lower unit cost-making SN74LVC2G125 optimal for precision timing-critical or independently controlled dual-channel use cases.

Availability

SN74LVC2G125 is available at Aetrix Electronics and suitable for industrial motor control, high-speed data acquisition, video broadcasting infrastructure, cable modem termination systems, and military radar subsystems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVC2G125 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 connectivity technologies, with decades of experience in high-reliability logic and interface solutions.

The SN74LVC2G125 belongs to TI's LVC (Low-Voltage CMOS) logic family, engineered for low-power, high-speed interoperability across mixed-voltage digital systems in industrial, communications, and automotive applications.

FAQ

What is the maximum operating frequency supported by the SN74LVC2G125?

The SN74LVC2G125 does not specify a hard maximum clock frequency, but its 4.3-ns typical propagation delay at 3.3 V supports reliable data transmission up to approximately 100 MHz in well-terminated, low-capacitance paths. Actual usable frequency depends on load capacitance, PCB trace impedance, and signal integrity margins-designers should verify timing closure using worst-case tpd values from the datasheet's switching characteristics tables for SN74LVC2G125.

Can the SN74LVC2G125 safely interface a 5-V microcontroller with a 1.8-V FPGA?

Yes-the SN74LVC2G125 accepts input voltages up to 5.5 V regardless of VCC level, allowing direct connection of 5-V MCU outputs to its 1A/2A pins while powered from 1.8 V. Its outputs swing rail-to-rail (0 V to 1.8 V), making them fully compatible with 1.8-V FPGA inputs. This eliminates external level-shifting components and preserves timing integrity, provided OE pins are properly biased during power sequencing for SN74LVC2G125.

Does the SN74LVC2G125 require external pull-up resistors on its OE pins?

Yes-TI recommends tying each OE pin (1OE, 2OE) to VCC through a pull-up resistor to ensure a defined high state during power-up or brownout conditions. The minimum resistor value depends on the current-sinking capability of the driving source; for standard CMOS drivers, 10-kΩ is commonly used. This guarantees the outputs remain in high-impedance mode until firmware actively asserts OE low, preventing bus contention in SN74LVC2G125-based systems.

How does the Ioff feature of the SN74LVC2G125 protect against back-drive current?

The Ioff circuitry in SN74LVC2G125 disables all outputs and isolates inputs when VCC = 0 V, limiting leakage to ±10 µA per pin. This prevents current from flowing backward through the device-for example, from a powered 3.3-V bus into an unpowered 1.8-V domain-thereby protecting downstream ICs and avoiding latch-up. This behavior is critical for hot-swap applications and is validated across the full –40°C to +125°C range for SN74LVC2G125.

Is the SN74LVC2G125 pin-compatible with other members of the SN74LVC2Gxx dual-gate family?

No-while SN74LVC2G125 shares the VSSOP-8 (DCUR) package with several dual-gate devices, pin assignments differ significantly. For example, SN74LVC2G00 (dual NAND) places inputs and outputs on different pins than SN74LVC2G125. Always verify pin functions using the "Pin Functions" table in the official SN74LVC2G125 datasheet-substituting based solely on package compatibility risks functional failure or damage.