Texas Instruments SN74LVT125D

Overview

SN74LVT125D from Texas Instruments is a quad 3-state noninverting buffer designed for mixed-voltage system interfacing, supporting 5-V TTL inputs/outputs with 3.3-V V_CC, operating down to 2.7 V, and featuring bus-hold inputs and I_off protection. It enables level translation between legacy 5-V logic and modern 3.3-V buses in industrial control backplanes.

For engineers reviewing the SN74LVT125D datasheet, SN74LVT125D pinout, SN74LVT125D application, or SN74LVT125D equivalent, key selection criteria include its 3.3-V supply tolerance, 5-V tolerant inputs, bus-hold functionality eliminating external pullups, I_off support for partial-power-down operation, and SOIC-14 package compatibility with legacy PCB layouts.

Technical Context

The SN74LVT125D implements four independent noninverting buffers, each with an active-low output-enable (OE) control enabling high-impedance state on Y when OE = HIGH. Its bus-hold circuitry actively maintains valid logic levels at unused A inputs without external resistors, reducing BOM count and layout complexity.

Designed for mixed-mode signal environments, it accepts 5-V TTL-level inputs while powered from 3.3-V V_CC, and drives 5-V-tolerant outputs - verified by VI absolute max rating of 7 V and VO rating up to 7 V. The I_off feature disables all outputs when V_CC = 0, preventing current backflow during power sequencing.

Key Specifications

Pinout & Package

SN74LVT125D uses a 14-pin SOIC (D) package with 1.27-mm pitch, 8.75-mm body width, and 1.75-mm max height - compatible with standard SOIC-14 footprints and reflow profiles (MSL Level-1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH125D and 74ALVC125D, the SN74LVT125D uniquely combines 5-V input tolerance, bus-hold, and 64-mA drive in a single SOIC-14 package - making it irreplaceable in legacy-to-modern voltage bridging where reliability and design simplicity are critical.

Availability

SN74LVT125D is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy bus extension, hot-swappable module designs, and low-power sensor hub buffering requiring stable component supply and long-term manufacturability.

Supply support for SN74LVT125D 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 delivering analog, embedded processing, and connectivity solutions with emphasis on industrial, automotive, and communications markets.

The SN74LVT125D belongs to TI's LVT (Low-Voltage BiCMOS Technology) logic family, engineered specifically for robust mixed-voltage interfacing in industrial control, test equipment, and telecom infrastructure where reliability across voltage domains is essential.

FAQ

What is the maximum input voltage the SN74LVT125D can tolerate?

The SN74LVT125D supports input voltages up to 7 V per absolute maximum ratings, allowing direct connection to 5-V TTL outputs without external clamping or level-shifting circuitry. This 5-V tolerance is maintained across the full operating temperature range (−40°C to 85°C) and is explicitly validated in the datasheet's VI specification table.

Does the SN74LVT125D require external pullup resistors on its inputs?

No, the SN74LVT125D does not require external pullup resistors because it integrates active bus-hold circuitry on all A inputs. This feature maintains unused or undriven inputs at valid logic levels, eliminating BOM cost and layout area typically needed for discrete pullups - confirmed in the device description and functional specifications.

Can the SN74LVT125D operate safely during partial power-down sequences?

Yes, the SN74LVT125D supports safe partial-power-down operation via its I_off circuitry, which disables outputs and limits leakage to ±100 µA when V_CC = 0. This prevents damaging current backflow from live 5-V buses into unpowered sections - a requirement explicitly verified per JEDEC JESD-78 and documented in the electrical characteristics table.

What is the propagation delay performance of the SN74LVT125D at 3.3 V?

At V_CC = 3.3 V, the SN74LVT125D delivers t_PLH and t_PHL values ranging from 1 ns (min) to 4.9 ns (max), with typical values at 2.7 ns. These figures are measured under CL = 50 pF and represent guaranteed timing for high-speed bus buffering in real-world industrial applications.

Is the SN74LVT125D pin-compatible with other 14-pin quad buffer devices?

The SN74LVT125D shares the industry-standard SOIC-14 pinout for quad 3-state noninverting buffers (1OE–1A–1Y–2OE–2A–2Y–GND–V_CC–4OE–4A–4Y–3OE–3A–3Y), matching pin-for-pin layouts of SN74LVC125A, SN74LVTH125, and 74ALVC125. Mechanical compatibility is confirmed by TI's D-package outline drawing D0014A.