Texas Instruments SN74ALVC125NSRE4

Overview

SN74ALVC125NSRE4 from Texas Instruments is a quadruple bus buffer gate with 3-state outputs, designed for 1.65 V to 3.6 V VCC operation. It provides four independent non-inverting buffers, each controlled by its own output-enable (OE) input, delivering ±24-mA drive at 3.3 V and achieving 2.8 ns max propagation delay. It serves as a level-shifting, bus-isolation, and signal fan-out component in low-voltage digital systems such as FPGA I/O interfacing and memory address/data buffering.

For engineers reviewing the SN74ALVC125NSRE4 datasheet, SN74ALVC125NSRE4 pinout, SN74ALVC125NSRE4 application, or SN74ALVC125NSRE4 equivalent, key selection criteria include 3-state control per channel, 1.65–3.6 V supply compatibility, ±24-mA drive strength at 3.3 V, 2.8 ns tpd, and SOP-14 (NS) package thermal performance (θJA = 76°C/W).

Technical Context

This device implements four independent CMOS buffer stages, each with active-low 3-state control logic: output Y goes high-impedance when OE is high. Input thresholds are VIL ≤ 0.35×VCC (at 1.65–1.95 V), VIH ≥ 0.65×VCC - enabling robust noise margin across its full 1.65–3.6 V operating range.

Each buffer supports bidirectional voltage translation between mixed-supply domains (e.g., 1.8 V logic driving 3.3 V bus), with rail-to-rail input tolerance (VI = 0 to VCC) and output swing (VO = 0 to VCC). Latch-up immunity exceeds 250 mA per JESD 17, and ESD protection meets 2000-V HBM, 200-V MM, and 1000-V CDM standards.

Key Specifications

Pinout & Package

SOP-14 (NS) package: 14-pin small-outline plastic package, 5.3 mm × 10.2 mm body, 1.75 mm max height, 1.27 mm lead pitch, gull-wing leads, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC125APWR, SN74ALVC125NSRE4 delivers tighter timing (2.8 ns vs. 3.1 ns) and better thermal performance in SOP-14; compared with 74ALVC125MTCX, it offers superior thermal dissipation (76 vs. 113°C/W) at the cost of larger footprint - making SN74ALVC125NSRE4 optimal for thermally constrained, timing-critical 14-pin SOP designs.

Availability

SN74ALVC125NSRE4 is available at Aetrix Electronics and suitable for memory subsystems, FPGA I/O expansion, sensor hub interfaces, and industrial PLC modules requiring stable component supply across automotive-grade temperature ranges (–40°C to 85°C).

Supply support for SN74ALVC125NSRE4 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, low-power logic families.

The ALVC (Advanced Low-Voltage CMOS) product line was engineered for high-speed, low-voltage digital interfacing in portable, industrial, and communications equipment - emphasizing rail-to-rail operation, robust ESD/latch-up immunity, and seamless voltage-domain bridging.

FAQ

What is the recommended power-up sequence for SN74ALVC125NSRE4?

TI recommends powering VCC before applying any input signals. To ensure outputs remain in high-impedance state during power-up, tie all OE inputs to VCC via pull-up resistors (minimum value determined by driver sink capability). This prevents bus contention or unintended signal assertion before system initialization completes. The SN74ALVC125NSRE4 does not require special reset sequencing beyond standard CMOS power-rail ordering.

Can SN74ALVC125NSRE4 interface between 1.8 V and 3.3 V logic domains?

Yes, SN74ALVC125NSRE4 supports true bidirectional voltage translation: its inputs accept 0–VCC levels, and outputs swing rail-to-rail (0 to VCC). When powered at 1.8 V, it reliably interprets 3.3 V inputs (within absolute max VI = –0.5 to VCC + 0.5 V), and when powered at 3.3 V, it drives 1.8 V–compatible loads. No external level shifters are needed for this cross-voltage buffering role.

What is the maximum capacitive load SN74ALVC125NSRE4 can drive while maintaining 2.8 ns propagation delay?

The 2.8 ns max tpd is specified under standard test conditions: CL = 30 pF for VCC = 1.8 V, CL = 30 pF for VCC = 2.5 V, and CL = 50 pF for VCC = 3.3 V. Driving >50 pF at 3.3 V increases tpd nonlinearly - TI characterizes tpd up to 50 pF in the datasheet. For loads exceeding 50 pF, derate timing using the provided CL vs. tpd curves or add series termination to maintain signal integrity.

Does SN74ALVC125NSRE4 require external pull-up resistors on OE pins?

Yes - to guarantee high-impedance state during power-up or power-down, TI specifies tying each OE input to VCC through a pull-up resistor. The minimum resistor value depends on the current-sinking capability of the controlling driver; for typical microcontroller GPIO (±20 mA), 10 kΩ is sufficient. Leaving OE floating risks undefined output states and potential bus contention.

Is SN74ALVC125NSRE4 compatible with lead-free reflow profiles?

Yes, SN74ALVC125NSRE4 is RoHS-compliant with NiPdAu lead finish and rated for MSL Level-1 (unlimited floor life) at peak reflow temperatures up to 260°C. Its SOP-14 (NS) package supports standard JEDEC J-STD-020 lead-free reflow profiles, including ramp-to-spike and soak profiles, with no special pre-bake required for moisture-sensitive handling.