Texas Instruments SN74LVTH126NSR

Overview

SN74LVTH126NSR from Texas Instruments is a quad 3-state noninverting buffer designed for mixed-mode 3.3-V V_CC bus interfacing with 5-V TTL systems. It supports hot insertion via I_off and power-up 3-state, features bus-hold on all data inputs, operates down to 2.7 V, and delivers 64 mA sink current per output - used in industrial backplane interface and legacy system bridging applications.

For engineers reviewing the SN74LVTH126NSR datasheet, SN74LVTH126NSR pinout, SN74LVTH126NSR application, or SN74LVTH126NSR equivalent, key selection criteria include its 14-pin SOP-NS package, 2.7–3.6 V supply range, 3.8 ns typical propagation delay at 3.3 V, bus-hold input retention, and hot-swap capability without external resistors.

Technical Context

The SN74LVTH126NSR implements four independent noninverting buffers, each with active-high output-enable (OE) control and high-impedance state when OE is low. Its bus-hold circuitry actively maintains valid logic levels on undriven inputs without external pullups, eliminating board-level resistor networks.

Designed for voltage translation between 3.3-V logic domains and 5-V TTL buses, it tolerates 5.5-V inputs while powered from 3.3-V V_CC, and includes I_off protection that disables outputs during power-down to prevent backflow current - critical for live-insertion systems.

Key Specifications

Pinout & Package

SOP-NS package: 14-pin small-outline plastic, 8.1 mm × 10.4 mm body, 1.27 mm pitch, 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 quad noninverting buffer applications.

Compared with SN74LVC126APW and SN74AHCT126N, the SN74LVTH126NSR uniquely combines 3.3-V operation, 5-V-tolerant inputs, bus-hold, and hot-swap readiness - making it irreplaceable in mixed-domain industrial upgrades without layout or firmware changes.

Availability

SN74LVTH126NSR is available at Aetrix Electronics and suitable for industrial backplane interface, legacy system bus bridging, and hot-swappable module control requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVTH126NSR 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 over 90 years of innovation in industrial, automotive, and communications markets.

The SN74LVTH126NSR belongs to TI's LVTH logic family, engineered specifically for robust 3.3-V/5-V mixed-signal interfacing in harsh environments - emphasizing hot-swap safety, latch-up immunity, and bus stability without external components.

FAQ

What is the maximum input voltage the SN74LVTH126NSR can tolerate while operating at 3.3 V?

The SN74LVTH126NSR supports an input voltage range of −0.5 V to 5.5 V when powered from 3.3 V V_CC. This allows direct connection to 5-V TTL outputs without level-shifting circuitry. The device maintains full functionality and ESD protection compliance across this range, as verified in the absolute maximum ratings and electrical characteristics tables of the SCBS746B datasheet.

Does the SN74LVTH126NSR require external pullup or pulldown resistors on its data inputs?

No, the SN74LVTH126NSR does not require external pullup or pulldown resistors because it integrates active bus-hold circuitry on all data inputs (A1–A4). This feature maintains the last valid logic state on undriven or floating inputs, eliminating risk of metastability or undefined behavior. Using external resistors with bus-hold is explicitly discouraged in the datasheet.

Can the SN74LVTH126NSR be used in hot-swap applications?

Yes, the SN74LVTH126NSR is explicitly designed for hot-insertion applications. It incorporates I_off circuitry that disables outputs during power-down to prevent damaging current backflow, and power-up 3-state logic that holds outputs in high-impedance until V_CC stabilizes - both confirmed in the functional description and absolute maximum ratings sections of the SCBS746B datasheet.

What is the thermal resistance (θ_JA) of the SN74LVTH126NSR in its SOP-NS package?

The SN74LVTH126NSR in the SOP-NS package has a junction-to-ambient thermal resistance (θ_JA) of 76°C/W, as specified in the "absolute maximum ratings" table of the SCBS746B datasheet. This value assumes standard JEDEC high-K board conditions and confirms suitability for industrial ambient temperatures up to +85°C without forced airflow or heatsinking.

How many independent buffers does the SN74LVTH126NSR contain, and what is their control architecture?

The SN74LVTH126NSR contains four independent noninverting buffers, each with its own dedicated output-enable (OE) input and data input (A). Each OE controls only its associated buffer output (Y), enabling granular bus segmentation. This architecture is confirmed by the logic diagram, pinout diagram, and function table in the SCBS746B datasheet - all showing discrete 1OE/1A/1Y through 4OE/4A/4Y channels.