Texas Instruments SN74LV125ATDB

Overview

SN74LV125ATDB from Texas Instruments is a quadruple 3-state bus buffer gate IC used for bidirectional data isolation and bus driving in 5-V digital systems. It features four independent channels, TTL-compatible inputs, 4.5–5.5-V operation, 3.8-ns typical propagation delay at 5 V, and Ioff support for partial-power-down mode. It is commonly deployed in microcontroller peripheral expansion, memory address/data bus buffering, and mixed-voltage interface translation.

For engineers reviewing the SN74LV125ATDB datasheet, SN74LV125ATDB pinout, SN74LV125ATDB application, or SN74LV125ATDB equivalent, key selection considerations include 3-state output timing (tdis/ten), ground bounce (VOLP < 0.8 V) and undershoot (VOHV > 2.3 V) performance, Ioff leakage (<5 µA), and SSOP-14 package thermal resistance (RθJA = 96 °C/W).

Technical Context

The SN74LV125ATDB implements four independent non-inverting buffers, each with an active-low 3-state output-enable (OE) input. Each channel operates as a voltage-level translator supporting mixed-mode voltage operation across all ports, enabling interfacing between 3.3-V logic and 5-V buses without level shifters.

Its Ioff circuitry actively disables outputs during power-down to prevent backflow current, and its latch-up immunity exceeds 250 mA per JESD17. The device uses standard CMOS process technology with TTL-input threshold compatibility and robust noise margins (VIH = 2 V, VIL = 0.8 V at VCC = 4.5–5.5 V).

Key Specifications

Pinout & Package

SN74LV125ATDB is housed in a 14-pin SSOP (Shrink Small Outline Package) with 0.65-mm lead pitch, 6.20 mm × 7.80 mm body size, and 2.0-mm max height. The package is RoHS-compliant, lead-finished with NiPdAu, and rated MSL Level-1 (unlimited floor life at ≤30°C/60% RH).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV125ATDB, SN74LVC125APW offers better low-voltage efficiency but cannot replace it in 5-V or mixed-voltage roles, while 74ACT125SCX delivers higher speed and drive at the cost of power-down safety and extended temperature compliance.

Availability

SN74LV125ATDB is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and embedded computing applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for SN74LV125ATDB 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 SN74LV125ATDB belongs to TI's LV logic family, designed specifically for robust 5-V digital interfacing in harsh environments-emphasizing low noise, power-down safety, and wide temperature operation.

FAQ

What is the recommended power-up sequence for SN74LV125ATDB to avoid bus contention?

TI recommends tying all OE pins to VCC through a pullup resistor (typically 10 kΩ) during power-up to force outputs into high-impedance state until firmware initializes control lines. This prevents unintended bus driving before system configuration completes. The SN74LV125ATDB Ioff feature further protects against backfeed if VCC ramps after other rails. Always verify OE timing relative to VCC stabilization in your power sequencing plan.

Does SN74LV125ATDB support hot-swapping in live backplane systems?

Yes - the SN74LV125ATDB supports hot-swap operation via its Ioff circuitry, which limits input/output leakage to <5 µA when VCC = 0 V. This prevents damaging current flow from live backplane traces into unpowered modules. However, mechanical insertion must occur within MSL-1 handling limits, and board-level TVS protection is advised for sustained 5-V backplane exposure.

Can SN74LV125ATDB safely interface a 3.3-V FPGA I/O bank with a 5-V EEPROM?

Yes - the SN74LV125ATDB supports mixed-mode voltage operation: its inputs accept 3.3-V logic levels (VIH = 2 V min), and its outputs drive 5-V compatible loads (VOH ≥ 3.8 V at 16 mA). No external level shifter is needed. Ensure OE is controlled by the FPGA's 3.3-V domain and confirm EEPROM input thresholds align with SN74LV125ATDB's VOL (≤0.55 V) and VOH (≥3.8 V) specs.

What is the maximum capacitive load SN74LV125ATDB can drive while maintaining 3.8-ns propagation delay?

The 3.8-ns typical tpd for SN74LV125ATDB is specified at CL = 15 pF. At CL = 50 pF, tpd increases to 5.3 ns. For designs requiring ≤4 ns delay, keep total load (including trace capacitance and receiver input) below 20 pF. Use series termination or reduce fanout if driving multiple loads - each additional 10 pF adds ~0.6 ns to tpd per channel.

How does SN74LV125ATDB mitigate ground bounce in high-speed bus applications?

The SN74LV125ATDB limits ground bounce (VOLP) to <0.8 V at VCC = 5 V, TA = 25°C via optimized output stage design and internal current-limiting. This is achieved without sacrificing 16-mA drive strength. To maintain this spec, use solid ground planes, place 0.1-µF decoupling caps within 5 mm of VCC/GND pins, and avoid routing sensitive analog traces near GND pin 7.