Texas Instruments SN74LVT125QDRG4Q1

Overview

SN74LVT125QDRG4Q1 from Texas Instruments is an automotive-qualified 3.3-V ABT quadruple bus buffer with 3-state outputs, featuring four independent noninverting drivers, bus-hold inputs, Ioff partial-power-down support, and mixed-mode 5-V/3.3-V signal compatibility - used in automotive infotainment data buses for level-shifting and load isolation.

For engineers reviewing the SN74LVT125QDRG4Q1 datasheet, SN74LVT125QDRG4Q1 pinout, SN74LVT125QDRG4Q1 application, or SN74LVT125QDRG4Q1 equivalent, key selection criteria include 3.3-V VCC operation with 5-V tolerant inputs, –40°C to 125°C automotive temperature range, SOIC-14 package, 32-mA output drive, and bus-hold functionality eliminating external pullups.

Technical Context

This device implements four independent noninverting buffer channels, each controlled by a dedicated output-enable (OE) input that places the corresponding Y output in high-impedance state when asserted high. Bus-hold circuitry actively maintains valid logic levels on unused A inputs without external resistors.

The SN74LVT125QDRG4Q1 supports unregulated battery operation down to 2.7 V and features Ioff protection that disables outputs during power-down to prevent backflow current. Its TTL-compatible interface enables interoperability between 3.3-V logic domains and legacy 5-V systems.

Key Specifications

Pinout & Package

SN74LVT125QDRG4Q1 is housed in a 14-pin SOIC (D) package, 8.75 mm × 3.91 mm footprint, 1.75 mm max height, RoHS-compliant NIPDAU lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVT125QDRG4Q1, SN74LVC125AQPWRQ1 offers lower cost but sacrifices bus-hold and robust Ioff behavior, while SN74LVTH125QPWRQ1 delivers higher output current and improved noise immunity at comparable automotive qualification - making it ideal for electrically demanding vehicle networks.

Availability

SN74LVT125QDRG4Q1 is available at Aetrix Electronics and suitable for automotive infotainment, ADAS sensor interfaces, body control modules, telematics gateways, and other applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVT125QDRG4Q1 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, personal electronics, and communications markets.

The SN74LVT125QDRG4Q1 belongs to TI's automotive-qualified ABT logic family, designed specifically for robust, low-voltage bus buffering in harsh-temperature vehicle subsystems where reliability, mixed-voltage interoperability, and power sequencing safety are critical.

FAQ

What is the operating temperature range for SN74LVT125QDRG4Q1?

The SN74LVT125QDRG4Q1 is rated for continuous operation from –40°C to +125°C ambient temperature. This Grade 1 automotive qualification ensures reliable performance in engine bay, dashboard, and powertrain control environments where thermal cycling and sustained high temperatures occur. The device meets AEC-Q100 requirements and is tested across this full range for parametric stability and functional integrity.

Does SN74LVT125QDRG4Q1 support 5-V input signals while powered from 3.3 V?

Yes, SN74LVT125QDRG4Q1 supports mixed-mode signal operation: its inputs tolerate up to 5.5 V regardless of VCC, enabling direct connection to 5-V TTL or CMOS sources while operating from a 3.3-V supply. This eliminates level-shifter ICs in legacy-to-modern interface designs. Input voltage range is specified from –0.5 V to 7 V, with VIH = 2.0 V and VIL = 0.8 V at VCC = 3.3 V.

How does the bus-hold feature work on SN74LVT125QDRG4Q1?

The bus-hold circuitry on SN74LVT125QDRG4Q1 actively retains the last-valid logic state on any undriven A input, drawing ±75 µA at VI = 2 V. It eliminates the need for external pullup or pulldown resistors, reducing BOM count and board space. TI explicitly warns against using external resistors with bus-hold enabled, as they may conflict with internal feedback and cause metastability or increased power draw.

Is SN74LVT125QDRG4Q1 pin-compatible with standard SN74LVT125 variants?

Yes, SN74LVT125QDRG4Q1 shares identical pinout, electrical characteristics, and functional behavior with non-automotive SN74LVT125 variants in SOIC-14 (D) package, including SN74LVT125DR and SN74LVT125D. The Q1 suffix denotes AEC-Q100 qualification and enhanced process controls, but pin assignment, logic function, and timing parameters remain fully aligned per TI's datasheet revision history and package drawings.

What is the maximum output current capability of SN74LVT125QDRG4Q1?

SN74LVT125QDRG4Q1 provides ±32 mA output drive per channel under recommended conditions (VCC = 3.3 V, TA = 25°C). Specifically, IOL = 32 mA guarantees VOL ≤ 0.5 V at VCC = 3 V, and IOH = –32 mA ensures VOH ≥ 2.0 V. This drive strength supports direct interfacing with standard TTL loads and multiple CMOS inputs without external buffering, verified across the full –40°C to +125°C operating range.