Texas Instruments SN74LVC126APW

Overview

SN74LVC126APW from Texas Instruments is a quadruple bus buffer gate with independent 3-state outputs, designed for 1.65V–3.6V V_CC operation. It delivers 24 mA output drive at 3 V, supports 5.5 V-tolerant inputs, achieves 4.7 ns max propagation delay at 3.3 V, and operates across –40°C to +125°C - enabling use in high-speed digital interface buffering for consumer audio/video systems.

For engineers reviewing the SN74LVC126APW datasheet, SN74LVC126APW pinout, SN74LVC126APW application, or SN74LVC126APW equivalent, this page provides verified functional identity, TSSOP-14 package mapping, 3-state timing parameters, voltage translation capability, thermal derating data, and validated alternative options for mixed-voltage logic interfacing.

Technical Context

The SN74LVC126APW implements four independent non-inverting buffers (Y = A), each controlled by its own active-low output-enable (OE) input. Its CMOS design ensures balanced rise/fall times and rail-to-rail output swing (0 V to V_CC), with input thresholds defined relative to V_CC and guaranteed 5.5 V tolerance regardless of supply voltage.

Each buffer transitions between low-impedance drive and high-impedance state under OE control; power-up/down robustness requires OE tied to GND via pulldown resistor. The device supports bidirectional voltage translation - accepting 5 V inputs while driving 3.3 V or lower logic loads - and exhibits <0.8 V typical ground bounce (V_OLP) and >2 V typical VOH undershoot (V_OHV) at 3.3 V.

Key Specifications

Pinout & Package

TSSOP-14 (PW) package: 5.00 mm × 4.40 mm body size, 14-pin surface-mount, exposed thermal pad connected to GND for enhanced thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC126APW, SN74LVC125APW changes OE polarity but preserves all electrical performance, while 74LVC126PW,118 trades 0.8 ns propagation delay for multi-source availability - both require validation of OE timing alignment and board-level noise immunity in final design.

Availability

SN74LVC126APW is available at Aetrix Electronics and suitable for audio/video interface buffering, memory bus isolation, mixed-voltage translation, and industrial control signal conditioning requiring stable component supply and full temperature-range qualification.

Supply support for SN74LVC126APW 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 high-reliability interface ICs.

The SN74LVC126APW belongs to TI's LVC logic family, engineered for low-voltage, high-speed, mixed-signal interfacing in consumer, industrial, and communications equipment where voltage translation and timing precision are critical.

FAQ

What is the maximum operating frequency supported by the SN74LVC126APW?

The SN74LVC126APW does not specify a maximum clock frequency directly, but its 4.7 ns maximum propagation delay at 3.3 V implies reliable operation up to approximately 100 MHz in well-terminated, low-capacitance signal paths. Actual usable frequency depends on load capacitance, PCB routing, and timing margins in the target application - design validation at 80 MHz is recommended for robustness.

Can the SN74LVC126APW safely interface a 5 V microcontroller with a 3.3 V FPGA?

Yes - the SN74LVC126APW accepts inputs up to 5.5 V regardless of V_CC, making it ideal for down-translation. When powered at 3.3 V, its outputs swing 0–3.3 V, matching FPGA I/O thresholds. Ensure OE pins are actively driven (not floating) and that output load current stays within ±24 mA per channel to maintain signal integrity.

Is the thermal pad on the SN74LVC126APW package required to be connected?

Yes - the exposed thermal pad on the SN74LVC126APW (TSSOP-14) must be soldered to a PCB ground plane using at least four thermal vias. This connection is essential for achieving the specified R_θJB = 93.8 °C/W and preventing junction temperature exceedance under sustained 24 mA output loading at +125°C ambient.

How should unused inputs be handled on the SN74LVC126APW?

All unused inputs (A or OE) on the SN74LVC126APW must be terminated to either V_CC or GND - never left floating. For unused OE pins, tie to GND to keep associated outputs disabled; for unused A inputs, tie to GND or V_CC based on desired default output state. Floating inputs cause increased ICC, noise susceptibility, and potential logic instability.

Does the SN74LVC126APW support hot-swap or live-insertion?

No - the SN74LVC126APW lacks explicit hot-swap protection features such as power-up sequencing control or back-drive immunity. Applying V_CC while signals are present on inputs or outputs may violate absolute maximum ratings. System-level hot-swap requires external circuitry (e.g., series resistors, dedicated hot-swap controllers) to limit inrush and ensure proper power sequencing before enabling SN74LVC126APW OE signals.