Texas Instruments SN74LV125ATDBG4

Overview

SN74LV125ATDBG4 from Texas Instruments is a quadruple 3-state bus buffer gate IC used for bidirectional data isolation and bus driving in digital logic systems. It operates from 4.5 V to 5.5 V, delivers typical propagation delay of 3.8 ns at 5 V, supports TTL-voltage-compatible inputs, and features Ioff partial-power-down protection. It is commonly deployed in industrial control backplanes and mixed-voltage interface bridging.

For engineers reviewing the SN74LV125ATDBG4 datasheet, SN74LV125ATDBG4 pinout, SN74LV125ATDBG4 application, or SN74LV125ATDBG4 equivalent, key selection considerations include 3-state output timing (tpd = 3.8 ns), Ioff leakage specification (≤5 µA), VCC operating range (4.5–5.5 V), and SSOP-14 package thermal resistance (RθJA = 96 °C/W).

Technical Context

The SN74LV125ATDBG4 implements four independent non-inverting buffers, each with active-low 3-state output enable (OE). Each channel operates with separate input (A) and output (Y) terminals, enabling selective bus gating without signal inversion. The device uses CMOS logic with TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V) and supports mixed-mode voltage operation across ports.

Its Ioff circuitry actively disables outputs during power-down, limiting input/output leakage to ≤5 µA when VCC = 0 V - critical for hot-swap and partial-power-down system architectures. Ground bounce (VOLP < 0.8 V) and VOH undershoot (VOHV > 2.3 V) are characterized at 5 V/25°C to ensure signal integrity in high-speed digital interfaces.

Key Specifications

Pinout & Package

VQFN-14 (RGY) and SSOP-14 (DB) packages are both supported; SN74LV125ATDBG4 specifically uses the SSOP-14 (DB) package: 6.20 mm × 7.8 mm body, 1.75 mm max height, gull-wing leads, JEDEC MO-150 compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV125ATDBG4, SN74LVC125APWR offers superior speed in 3.3-V domains but forfeits Ioff protection, while 74ACT125SCX delivers higher output current at the cost of static power and absence of power-down safety - making SN74LV125ATDBG4 the sole choice for mixed-mode, hot-pluggable, or thermally constrained industrial interfaces.

Availability

SN74LV125ATDBG4 is available at Aetrix Electronics and suitable for industrial automation backplanes, legacy system upgrades, and test equipment I/O expansion requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for SN74LV125ATDBG4 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 industrial-grade interface ICs and broad portfolio support for long-lifecycle applications.

The SN74LV125ATDBG4 belongs to TI's LV logic family, designed specifically for robust 5-V digital interfacing in harsh environments - emphasizing low noise, high ESD immunity, and safe partial-power-down operation.

FAQ

What is the maximum operating temperature for SN74LV125ATDBG4?

The SN74LV125ATDBG4 is rated for continuous operation from –40°C to +125°C ambient temperature. This extended range is validated per JEDEC JESD22-A108 and supports deployment in industrial control cabinets, automotive engine compartments, and outdoor infrastructure equipment where thermal stress is significant. Derating applies above 85°C per RθJA = 96 °C/W.

Does SN74LV125ATDBG4 support true bidirectional data flow?

No - SN74LV125ATDBG4 is a unidirectional non-inverting buffer with independent 3-state outputs. It does not contain internal direction control or bus transceivers. Data flows only from A-input to Y-output per channel; bidirectional operation requires external control logic or complementary devices like the SN74LV245A.

Can SN74LV125ATDBG4 be used with 3.3-V microcontrollers?

Yes - SN74LV125ATDBG4 accepts TTL-compatible inputs (VIH = 2 V min), so 3.3-V logic high levels safely meet its input threshold. However, its outputs swing rail-to-rail within 4.5–5.5 V, so direct connection to 3.3-V receivers requires level translation or clamping to avoid overvoltage damage.

What is the purpose of the Ioff specification in SN74LV125ATDBG4?

The Ioff feature in SN74LV125ATDBG4 limits input/output leakage to ≤5 µA when VCC = 0 V, preventing current backflow from live buses into a powered-down subsystem. This enables safe hot-swap insertion and power sequencing in modular industrial hardware where sections may be individually powered.

Is SN74LV125ATDBG4 pin-compatible with other 74-series quad buffers?

SN74LV125ATDBG4 shares the same SSOP-14 pinout as SN74LV125ADBR and SN74LV125ADR, but differs from 74LS125 or 74HC125 in electrical behavior (e.g., Ioff, VOLP, VCC range). Mechanical pin alignment is identical, but functional substitution requires verification of timing, drive strength, and power-down behavior.