Texas Instruments SN74AHCT1G125DRLR

Overview

SN74AHCT1G125DRLR from Texas Instruments is a single 3-state bus buffer gate designed for level translation and bus isolation in 5-V digital systems. It features TTL-compatible inputs, ±8 mA output drive at 5 V, 6 ns max propagation delay, and operates across 4.5 V to 5.5 V supply with 10 µA max ICC - enabling use in low-power server I/O control and wireless infrastructure backplane interfaces.

For engineers reviewing the SN74AHCT1G125DRLR datasheet, SN74AHCT1G125DRLR pinout, SN74AHCT1G125DRLR application, or SN74AHCT1G125DRLR equivalent, key selection criteria include its SOT-5X3 (DRL) 5-pin package, 3-state output enable control, 5-V-only operation, and compatibility with legacy TTL logic levels in space-constrained industrial and telecom designs.

Technical Context

The SN74AHCT1G125DRLR implements a noninverting single-channel buffer with active-low 3-state output enable (OE). Its input threshold is lowered to VIH = 2 V and VIL = 0.8 V, allowing reliable interfacing with 3.3-V TTL outputs while operating from a 5-V supply. The device uses CMOS technology with balanced output drive and intentionally slow edge rates to suppress ringing on lightly loaded buses.

It supports full 5-V operation only (no 3.3-V supply support), requires OE to be pulled high via external resistor during power-up to ensure default high-impedance state, and exhibits latch-up immunity exceeding 250 mA per JESD17. Thermal resistance RθJA is 328.7 °C/W in its DRL package, reflecting its ultra-small footprint and limited power dissipation capability.

Key Specifications

Pinout & Package

SOT-5X3 (DRL) package: 1.6 mm × 1.6 mm body size, 0.6 mm max height, 5-pin surface-mount outline with gull-wing leads and pin 1 identifier in quadrant Q3 per tape-and-reel specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHCT1G125DRLR, the DBVR offers superior thermal dissipation in a larger footprint, while the DCKR provides broader assembly compatibility at a moderate size trade-off - both retain identical logic function, timing, and voltage specifications.

Availability

SN74AHCT1G125DRLR is available at Aetrix Electronics and suitable for server baseboard management, wireless RRU control, and industrial PLC I/O expansion requiring stable component supply and long-term industrial temperature support.

Supply support for SN74AHCT1G125DRLR 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 50 years of innovation in high-reliability digital interface ICs.

The SN74AHCT1G125 series targets space- and power-constrained digital interface applications requiring robust 5-V TTL compatibility, 3-state bus control, and industrial-grade reliability - especially in telecom, computing, and automation infrastructure.

FAQ

What is the maximum operating supply voltage for SN74AHCT1G125DRLR?

The SN74AHCT1G125DRLR has an absolute maximum supply voltage of 7 V, but its recommended operating range is strictly 4.5 V to 5.5 V. Operation outside this window may cause timing violations, increased ICC, or reduced noise margin. The SN74AHCT1G125DRLR is not rated for 3.3-V operation and must be powered from a regulated 5-V source.

Does SN74AHCT1G125DRLR support 3.3-V input logic levels?

Yes - the SN74AHCT1G125DRLR features TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V), allowing direct connection to 3.3-V CMOS or TTL outputs. Inputs tolerate up to 5.5 V regardless of VCC, making the SN74AHCT1G125DRLR ideal for 3.3-V-to-5-V level translation without external components.

How should the OE pin be handled during power-up for SN74AHCT1G125DRLR?

To ensure the output Y remains in high-impedance state at power-up, OE must be held high via an external pullup resistor to VCC. TI recommends sizing the resistor based on the driver's current-sinking capability; typical values range from 4.7 kΩ to 10 kΩ. Leaving OE floating risks undefined output states and potential bus contention in the SN74AHCT1G125DRLR.

What is the thermal resistance of SN74AHCT1G125DRLR in its SOT-5X3 package?

The SN74AHCT1G125DRLR in the DRL package has a junction-to-ambient thermal resistance (RθJA) of 328.7 °C/W. This reflects its ultra-compact 1.6 mm × 1.6 mm body and limits continuous power dissipation to ~15 mW at 25 °C ambient. For sustained operation, keep total power below 10 mW or implement board-level thermal relief in the SN74AHCT1G125DRLR layout.

Can SN74AHCT1G125DRLR drive a 50-pF load within its specified timing?

Yes - the SN74AHCT1G125DRLR switching characteristics are characterized up to 50 pF load capacitance. At VCC = 5 V and TA = 25 °C, tPLH/tPHL is 5.3–7.5 ns and tPHZ/tPLZ is 6.1–11 ns into 50 pF. These values remain within datasheet limits across –40 °C to +125 °C, confirming reliable operation with typical PCB trace and connector capacitance in the SN74AHCT1G125DRLR application.