Texas Instruments SN74AHC126PWR

Overview

SN74AHC126PWR 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 features latch-up immunity exceeding 250 mA per JESD 17 - used in logic-level translation, transmission line driving, and LED indicator control.

For engineers reviewing the SN74AHC126PWR datasheet, SN74AHC126PWR pinout, SN74AHC126PWR application, or SN74AHC126PWR equivalent, key selection criteria include 14-pin TSSOP package compatibility, 3-state output timing behavior under 15 pF/50 pF loads, input transition rate limits (20–100 ns/V), and thermal performance (R_θJA = 147.7°C/W) in industrial temperature range (–40°C to +85°C).

Technical Context

The SN74AHC126PWR implements four identical non-inverting buffer channels, each with separate active-low output enable (OE) control and CMOS-compatible inputs. Its balanced 3-state outputs provide symmetrical sourcing/sinking capability up to ±25 mA, enabling bidirectional bus contention management without external pull resistors during high-impedance states.

Each channel operates as Y = A in positive logic, with defined functional modes across OE/A combinations: OE = L forces Y = Z (high-Z), while OE = H passes A to Y. Input thresholds scale with V_CC (e.g., V_IL = 0.9 V at 3 V, V_IH = 3.85 V at 5.5 V), ensuring robust noise margins across supply voltages.

Key Specifications

Pinout & Package

TSSOP-14 (PW) package: 5 mm × 6.4 mm body size, 14-pin surface-mount, RoHS-compliant, NIPDAU/SN lead finish, MSL Level-1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC126APWR and 74AHC126PW,118, the SN74AHC126PWR offers broader voltage flexibility (up to 5.5 V), guaranteed 5 V interoperability, and superior latch-up immunity - making it optimal for mixed-voltage industrial designs where reliability under transient stress is critical.

Availability

SN74AHC126PWR is available at Aetrix Electronics and suitable for industrial control panels, test equipment interfaces, and embedded communication modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74AHC126PWR 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 experience in high-reliability industrial and automotive IC design.

The SN74AHC126PWR belongs to TI's AHC logic family, engineered for low-power, high-speed CMOS bus interfacing in space-constrained industrial and communications applications where signal integrity and supply voltage flexibility are essential.

FAQ

What is the maximum output current rating for SN74AHC126PWR?

The SN74AHC126PWR supports ±25 mA continuous output current per channel, verified across the full operating temperature range (–40°C to +85°C). This rating applies to both sourcing (I_OH) and sinking (I_OL) conditions at V_CC = 5 V, and is specified in the Absolute Maximum Ratings table of the official datasheet (SCLS257N). Exceeding this limit risks thermal damage or latch-up.

Does SN74AHC126PWR support 5 V tolerant inputs when operated at 3.3 V V_CC?

No - SN74AHC126PWR is not 5 V tolerant. When V_CC = 3.3 V, the absolute maximum input voltage is 7 V, but the recommended operating condition limits VI to 0–V_CC (0–3.3 V). Applying 5 V to an input violates the Recommended Operating Conditions and may cause excessive leakage or reliability degradation. Use SN74LVC126 for true 5 V-tolerant 3.3 V operation.

How should unused inputs be handled on SN74AHC126PWR?

All unused inputs on SN74AHC126PWR - including A and OE pins - must be tied to either V_CC or GND. Floating CMOS inputs cause increased power consumption, oscillation, and potential device malfunction. A 10 kΩ pull-up or pull-down resistor is recommended for OE pins to ensure defined high-impedance state during power-up; unused A inputs may be directly connected.

What is the thermal resistance (R_θJA) of SN74AHC126PWR in its TSSOP package?

The SN74AHC126PWR in the PW (TSSOP-14) package has a junction-to-ambient thermal resistance (R_θJA) of 147.7°C/W, as documented in Section 5.4 of the SCLS257N datasheet. This value assumes standard JEDEC high-K board conditions; actual thermal performance depends on PCB copper area, airflow, and nearby heat sources.

Can SN74AHC126PWR be used as a level shifter between 2.5 V and 5 V logic domains?

Yes - SN74AHC126PWR can translate signals bidirectionally between 2.5 V and 5 V domains when powered at 5 V. Its input thresholds scale with V_CC, so a 2.5 V input exceeds V_IL (1.65 V) and remains below V_IH (3.85 V), ensuring valid logic recognition. Output swing will be rail-to-rail (0–5 V), requiring external resistive divider or receiver-side conditioning for 2.5 V-compatible inputs.