Texas Instruments SN74AHC126PWRG4

Overview

SN74AHC126PWRG4 from Texas Instruments is a quadruple bus buffer gate with independent 3-state outputs, designed for digital signal routing and bus isolation in 2V–5.5V systems. It delivers 3.8 ns typical propagation delay at 5 V, supports ±25 mA output drive, and operates across –40°C to +85°C - enabling use in industrial control backplanes and low-voltage FPGA I/O interface buffering.

For engineers reviewing the SN74AHC126PWRG4 datasheet, SN74AHC126PWRG4 pinout, SN74AHC126PWRG4 application, or SN74AHC126PWRG4 equivalent, key selection criteria include 3-state timing behavior under 15 pF/50 pF loads, input transition rate compliance (≤20 ns/V at 5 V), and thermal performance in TSSOP-14 packages with RθJA = 147.7°C/W.

Technical Context

The SN74AHC126PWRG4 implements four identical non-inverting buffer channels, each with separate active-low output enable (OE) control. Its CMOS architecture ensures symmetrical high/low drive strength (±4 mA at 3.3 V, ±8 mA at 5 V) and rail-to-rail output swing (VOL ≤ 0.1 V, VOH ≥ 4.4 V at 4.5 V).

Each channel operates independently: when OE is low, Y follows A; when OE is high, Y enters high-impedance state with leakage ≤ ±2.5 μA. Input thresholds scale with VCC (VIH = 3.85 V min at 5.5 V, VIL = 1.65 V max), supporting mixed-voltage interfacing without level shifters.

Key Specifications

Pinout & Package

TSSOP-14 (PW) package: 5 mm × 6.4 mm body, 14-pin surface-mount, RoHS-compliant with NIPDAU lead finish and MSL Level-1 rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHC126PWRG4, SN74AHCT126PWR offers TTL input compatibility but sacrifices 2–3.3 V operation, while 74LVC126APW,118 achieves lower delay and smaller size at the cost of 5 V tolerance - making SN74AHC126PWRG4 the optimal choice for broad-voltage industrial bus isolation.

Availability

SN74AHC126PWRG4 is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA I/O expansion, and microcontroller peripheral multiplexing requiring stable component supply across extended temperature ranges.

Supply support for SN74AHC126PWRG4 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 over 90 years of innovation in industrial, automotive, and communications markets.

The SN74AHC126 product line delivers high-speed, low-power bus buffering for digital signal routing in mixed-voltage systems - targeting industrial automation, test equipment, and programmable logic interconnect applications.

FAQ

What is the maximum operating frequency supported by SN74AHC126PWRG4?

The SN74AHC126PWRG4 does not specify a maximum clock frequency, but its 3.8 ns typical propagation delay at 5 V implies reliable operation up to approximately 260 MHz toggle rate. Actual usable frequency depends on load capacitance, trace routing, and supply stability - verified in TI's switching characteristics tables for 15 pF and 50 pF loads.

Can SN74AHC126PWRG4 interface between 3.3 V and 5 V logic domains?

Yes, SN74AHC126PWRG4 supports 2 V–5.5 V operation and features CMOS input thresholds that scale with VCC. When powered at 5 V, it accepts 3.3 V logic-high inputs (VIH min = 3.85 V at VCC = 5.5 V, but 3.3 V exceeds VIH = 2.1 V at VCC = 3 V). For robust 3.3 V → 5 V translation, operate SN74AHC126PWRG4 at 5 V and ensure upstream 3.3 V drivers meet VIH requirements.

How should unused inputs and outputs be handled on SN74AHC126PWRG4?

All unused inputs on SN74AHC126PWRG4 must be tied to VCC or GND - floating CMOS inputs cause excessive current draw and potential oscillation. Unused 3-state outputs may be left unconnected, but if bus termination is required, add a pull-up or pull-down resistor (e.g., 10 kΩ) to define voltage during high-impedance state. OE pins should be actively driven or pulled low via resistor to avoid unintended output disable.

Does SN74AHC126PWRG4 require external decoupling capacitors?

Yes, SN74AHC126PWRG4 requires local VCC–GND decoupling. TI recommends a 0.1 μF ceramic capacitor placed within 1 cm of pins 14 (VCC) and 7 (GND) to suppress switching noise and maintain stable supply during output transitions. For systems with multiple devices or high di/dt, add a bulk 4.7 μF capacitor nearby to reduce low-frequency ripple.

What is the thermal resistance of SN74AHC126PWRG4 in its TSSOP-14 package?

The SN74AHC126PWRG4 in TSSOP-14 (PW) package has a junction-to-ambient thermal resistance (RθJA) of 147.7°C/W under standard JEDEC test conditions. This value assumes a two-layer board with 1 in² copper area per side; actual thermal performance improves with additional copper pour, thermal vias, or heatsinking - critical for sustained ±8 mA output loading at elevated ambient temperatures.