Texas Instruments SN74LVC126APWRG4

Overview

SN74LVC126APWRG4 from Texas Instruments is a quadruple bus buffer gate with 3-state outputs, designed for 1.65V–3.6V V_CC operation. It provides independent line drivers with 5.5V-tolerant inputs, 4.7ns max propagation delay at 3.3V, 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 SN74LVC126APWRG4 datasheet, SN74LVC126APWRG4 pinout, SN74LVC126APWRG4 application, or SN74LVC126APWRG4 equivalent, key selection criteria include 3-state output timing (t_en/t_dis), 5.5V input tolerance for mixed-voltage translation, thermal performance in TSSOP-14, and latch-up immunity exceeding 250mA per JESD17.

Technical Context

The SN74LVC126APWRG4 implements four independent non-inverting buffers, each controlled by a dedicated active-low output-enable (OE) input. Its CMOS design supports Boolean function Y = A in positive logic, with outputs entering high-impedance state when OE is low - critical for bus sharing and signal isolation.

It features overvoltage-tolerant inputs (up to 5.5V regardless of V_CC), enabling down-translation from 5V logic to 1.8V/2.5V/3.3V domains. The device requires pulldown biasing of OE pins during power-up/down to guarantee defined high-Z behavior, and exhibits ground bounce (V_OLP) < 0.8V and undershoot (V_OHV) > 2V at 3.3V/25°C.

Key Specifications

Pinout & Package

TSSOP-14 (PW) package: 5.00mm × 4.40mm body size, 14-pin thin shrink small-outline package with exposed thermal pad connected to GND for enhanced thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC125APWRG4, the SN74LVC126APWRG4 offers native active-low OE control simplifying connection to open-drain reset supervisors; versus 74LVC126PW,118, it provides tighter parametric consistency across temperature and longer TI production lifecycle support.

Availability

SN74LVC126APWRG4 is available at Aetrix Electronics and suitable for AV receivers, solid-state drives, industrial HMI panels, and wireless peripheral hubs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVC126APWRG4 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 decades of expertise in logic IC design and automotive-grade qualification.

The SN74LVC126APWRG4 belongs to TI's LVC (Low-Voltage CMOS) logic family, engineered for high-speed, low-power, mixed-voltage interface bridging in consumer, industrial, and computing applications.

FAQ

What is the maximum operating voltage for inputs on the SN74LVC126APWRG4?

The SN74LVC126APWRG4 supports input voltages up to 5.5V regardless of V_CC level - a key feature enabling its use as a down-translator in mixed 3.3V/5V systems. This tolerance is specified across the full operating temperature range (–40°C to +125°C) and does not require external clamping circuitry. Inputs remain functional even when V_CC is as low as 1.65V, making SN74LVC126APWRG4 suitable for brown-out conditions in portable devices.

How does the SN74LVC126APWRG4 handle power-up sequencing to avoid bus contention?

To ensure high-impedance outputs during power-up and power-down, each OE pin of the SN74LVC126APWRG4 must be tied to GND through a pulldown resistor. TI specifies that the minimum resistor value depends on the current-sourcing capability of the driving source - typically 10kΩ suffices for most MCU GPIOs. This prevents undefined output states that could cause bus contention or excessive current draw before system initialization completes. The SN74LVC126APWRG4 does not include internal weak pull-downs on OE pins.

Can the SN74LVC126APWRG4 drive multiple CMOS loads simultaneously?

Yes, the SN74LVC126APWRG4 can drive multiple CMOS inputs due to its ±24mA output drive strength at V_CC = 3V and low output impedance. Each output supports up to 25mA DC current, and the total device current is limited to ±50mA. When driving multiple loads, designers must verify trace capacitance and maintain signal integrity - especially given its 4.7ns propagation delay at 3.3V. For fan-out >10, series termination or careful layout is recommended to suppress ringing.

What thermal considerations apply to the SN74LVC126APWRG4 in TSSOP-14 package?

The SN74LVC126APWRG4 in PW (TSSOP-14) package has a junction-to-ambient thermal resistance (R_θJA) of 150.8°C/W. To maintain safe operation at full drive strength and 125°C ambient, the PCB must incorporate adequate copper area connected to the exposed thermal pad via ≥4 thermal vias to an internal ground plane. Without proper thermal relief, power dissipation above 100mW may exceed the 150°C maximum junction temperature - particularly under sustained 24mA output loading.

Is the SN74LVC126APWRG4 pin-compatible with other members of the SN74LVC126A family?

Yes, all SN74LVC126A variants - including SN74LVC126APWRG4, SN74LVC126ADR, and SN74LVC126APW - share identical pinouts across SOIC, TSSOP, SSOP, TVSOP, WQFN, and VQFN packages. The TSSOP-14 (PW) footprint used by SN74LVC126APWRG4 is mechanically interchangeable with SN74LVC126APW and SN74LVC126APWR, differing only in tape-and-reel packaging and RoHS marking. No PCB redesign is needed when migrating between these variants.