Texas Instruments SN74ALVC126DGVR

Overview

SN74ALVC126DGVR from Texas Instruments is a quadruple bus buffer gate with 3-state outputs, designed for 1.65 V to 3.6 V VCC operation. It features four independent line drivers, ±24-mA output drive at 3.3 V, 3.1 ns max propagation delay, and latch-up performance exceeding 250 mA per JESD 17 - used in level-shifting and bidirectional data bus isolation in low-voltage embedded control systems.

For engineers reviewing the SN74ALVC126DGVR datasheet, SN74ALVC126DGVR pinout, SN74ALVC126DGVR application, or SN74ALVC126DGVR equivalent, key selection considerations include its TVSOP-14 package, 3-state enable control per channel, rail-to-rail input compatibility, and guaranteed 1.65 V minimum supply operation for mixed-voltage interface bridging.

Technical Context

This device implements four identical non-inverting buffers, each with an active-high output-enable (OE) input controlling high-impedance state. Each channel operates independently, enabling selective bus gating without inter-channel coupling. Input thresholds scale with VCC (VIH = 0.65×VCC min at 1.65 V), supporting robust logic-level translation across 1.8 V, 2.5 V, and 3.3 V domains.

Output drive strength is specified at ±24 mA under 3 V/3.3 V conditions, with VOL ≤ 0.55 V and VOH ≥ 2.0 V at full load. The design incorporates ESD protection per JESD 22 (2000-V HBM, 200-V MM, 1000-V CDM) and meets JEDEC JESD 17 latch-up immunity requirements.

Key Specifications

Pinout & Package

SN74ALVC126DGVR is housed in a 14-pin TVSOP (Thin Very Small Outline Package) with 0.5 mm pitch, 3.6 mm × 5.1 mm body size, and 1.2 mm max height - optimized for high-density PCB layouts and automated SMT assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALVC126DGVR, SN74LVC126APWRE4 offers extended thermal capability in identical packaging, while 74AVC126T14X extends voltage range downward to 1.2 V at faster speed - both require validation of board-level ESD robustness and thermal dissipation in final mechanical enclosure.

Availability

SN74ALVC126DGVR is available at Aetrix Electronics and suitable for industrial PLC backplane interfaces, low-power sensor hub data multiplexing, and USB-C docking station level-shifting requiring stable component supply and consistent TVSOP-14 sourcing.

Supply support for SN74ALVC126DGVR 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 50 years of innovation in high-reliability logic and interface solutions.

The ALVC logic family targets low-voltage, high-speed bus interface applications - engineered for voltage translation, noise-immune signal routing, and power-efficient 3-state control in space-constrained embedded systems.

FAQ

What is the minimum supply voltage required for reliable operation of the SN74ALVC126DGVR?

The SN74ALVC126DGVR is fully specified to operate down to 1.65 V VCC across the full -40°C to +85°C temperature range. Below this voltage, parameters such as propagation delay, output drive, and input threshold margins are not guaranteed. At 1.65 V, VIH is specified as 1.07 V min and VIL as 0.58 V max, ensuring functional logic behavior with adequate noise margin. Always verify timing closure in your specific application using worst-case VCC and temperature corners.

Does the SN74ALVC126DGVR support mixed-voltage interfacing between 1.8 V and 3.3 V systems?

Yes, the SN74ALVC126DGVR supports true mixed-voltage interfacing: inputs accept 0–VCC logic levels, so a 1.8 V signal applied to an A input will correctly drive the Y output at 3.3 V logic levels when VCC = 3.3 V. Its VIH/VIL thresholds scale with VCC, providing robust noise immunity across 1.65 V–3.6 V operation. No external biasing or level-shifting components are needed, making it ideal for bridging 1.8 V sensors to 3.3 V processors.

How should unused inputs be handled on the SN74ALVC126DGVR?

All unused inputs on the SN74ALVC126DGVR - including OE and A pins - must be tied to either VCC or GND to prevent floating states that cause increased ICC, erratic output behavior, or ESD susceptibility. TI recommends tying unused OE inputs to GND to ensure associated outputs remain in high-impedance state. Unused A inputs may be tied to VCC or GND depending on desired default output state, but never left unconnected. Refer to TI application report SCBA004 for detailed guidance.

What is the thermal resistance (θJA) of the SN74ALVC126DGVR in its TVSOP package?

The SN74ALVC126DGVR in the TVSOP (DGV) package has a specified junction-to-ambient thermal resistance (θJA) of 127 °C/W under standard JEDEC test conditions (1-layer board, 1 in² copper). This value assumes minimal PCB copper area; actual thermal performance improves significantly with added thermal vias and copper pour. For continuous 24 mA output loading at 85°C ambient, junction temperature remains below 125°C - well within safe operating limits.

Can the SN74ALVC126DGVR be used as a replacement for the older SN74LV126A?

The SN74ALVC126DGVR is not a direct drop-in replacement for SN74LV126A due to differences in input threshold definitions and timing. While both are quad 3-state buffers, SN74LV126A uses fixed VIH/VIL thresholds (e.g., VIH = 2.0 V min), whereas SN74ALVC126DGVR uses VCC-scaled thresholds. Also, SN74ALVC126DGVR has faster tpd (3.1 ns vs. 4.2 ns at 3.3 V) and higher drive (±24 mA vs. ±12 mA). Verify timing margins and logic threshold compatibility before substitution.