Texas Instruments SN74ABT126PW

Overview

SN74ABT126PW from Texas Instruments is a quadruple bus buffer gate with 3-state outputs in a 14-pin TSSOP package, operating at 4.5–5.5 V, delivering ±32 mA high-drive capability and supporting hot insertion via Ioff and power-up 3-state functionality. It is used in bidirectional data bus isolation and level translation in industrial control backplanes.

For engineers reviewing the SN74ABT126PW datasheet, SN74ABT126PW pinout, SN74ABT126PW application, or SN74ABT126PW equivalent, key selection criteria include guaranteed 3-state behavior during power ramp (0–2.1 V), low output ground bounce (<1 V), latch-up immunity (>500 mA), and compatibility with TTL-level inputs in 5-V systems.

Technical Context

This device implements four independent noninverting buffers, each with dedicated output-enable (OE) control. Each buffer transitions to high-impedance when its OE input is logic low, and remains in high-Z during power-up/down when VCC is between 0 and 2.1 V without external biasing.

It features TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V), supports fast switching (tPLH/tPHL ≤ 7.3 ns at 5 V), and includes robust ESD protection (2000-V HBM, 200-V MM) and current-limiting clamp diodes for system-level reliability.

Key Specifications

Pinout & Package

TSSOP-14 (PW) package: 4.4 mm × 5.0 mm body, 0.65 mm pitch, 1.2 mm max height, exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC126APW, SN74ABT126PW delivers guaranteed 5-V operation, higher drive, and intrinsic hot-swap safety; compared with SN74ABT244PW, it offers half the channel count in identical TSSOP-14 packaging for space-constrained designs requiring only four buffers.

Availability

SN74ABT126PW is available at Aetrix Electronics and suitable for industrial backplane isolation, memory address buffering, and test equipment signal routing requiring stable component supply and long-term production continuity.

Supply support for SN74ABT126PW 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 solutions, with decades of experience in logic and interface IC design.

The ABT logic family, including SN74ABT126PW, was engineered for high-speed, high-drive 5-V bus applications demanding robustness in industrial and instrumentation environments.

FAQ

What is the recommended pull-down resistor value for OE on SN74ABT126PW?

For reliable low-state assertion above 2.1 V VCC, TI recommends tying OE to GND through a pulldown resistor. The minimum value depends on the driver's current-sourcing capability; typical values range from 1 kΩ to 10 kΩ. SN74ABT126PW datasheet Section 6 specifies that OE must be ≤0.8 V to guarantee high-impedance output, and the resistor must sink sufficient current to maintain that threshold under worst-case noise and leakage conditions.

Does SN74ABT126PW support hot insertion in powered systems?

Yes, SN74ABT126PW supports hot insertion due to its Ioff specification (±100 μA at VCC = 0) and power-up 3-state behavior. When VCC is 0 V, all I/O pins draw minimal current, preventing backfeeding or disruption of live bus lines. This makes SN74ABT126PW suitable for modular systems where cards are inserted or removed without powering down the host backplane.

What is the thermal resistance θJA for SN74ABT126PW in its TSSOP package?

The junction-to-ambient thermal resistance (θJA) for SN74ABT126PW in the PW (TSSOP-14) package is 113°C/W, as specified in the Absolute Maximum Ratings table of the official datasheet. This value assumes standard JEDEC 2-layer board conditions and informs thermal design margining for continuous operation at maximum load and ambient temperature.

Can SN74ABT126PW interface directly with 3.3-V logic inputs?

Yes, SN74ABT126PW accepts 3.3-V logic inputs reliably: its VIH threshold is 2.0 V (min), and VIL is 0.8 V (max), both comfortably met by standard 3.3-V CMOS/TTL outputs. However, its outputs swing rail-to-rail (0–5 V), so interfacing with 3.3-V-only receivers requires external level translation or series termination to avoid overvoltage damage.

What is the maximum capacitive load SN74ABT126PW can drive while maintaining timing specs?

SN74ABT126PW is characterized with CL = 50 pF in switching specifications (e.g., tPLH/tPHL ≤ 7.3 ns). While it can drive heavier loads, timing degrades linearly with capacitance; for loads exceeding 50 pF, designers should verify setup/hold margins using the device's output impedance model and board trace parameters. The 64-mA IOL ensures robust edge rates even at 100 pF, but propagation delay increases approximately 0.1 ns/pF beyond 50 pF.