Texas Instruments 74AHC1G125DCKRE4

Overview

74AHC1G125DCKRE4 from Texas Instruments is a single 3-state bus buffer gate used for signal isolation and bidirectional bus control in low-power digital systems. It operates from 2 V to 5.5 V, delivers ±8 mA output drive at 5 V, achieves 3.8 ns typical propagation delay (tPLH/tPHL) at 5 V, and features 10 µA max ICC supply current. It is deployed in TV backplane interfaces, projector timing control, and patient monitoring data buses.

For engineers reviewing the 74AHC1G125DCKRE4 datasheet, 74AHC1G125DCKRE4 pinout, 74AHC1G125DCKRE4 application, or 74AHC1G125DCKRE4 equivalent, key selection criteria include its SC-70 (DCK) 5-pin package, 3-state output enable logic (active-low OE), rail-to-rail input tolerance up to 5.5 V, and guaranteed operation from –40°C to +125°C.

Technical Context

The 74AHC1G125DCKRE4 implements a noninverting buffer with tri-state output controlled by an active-low output-enable (OE) input. Its CMOS AHC logic family ensures compatibility with both 3.3 V and 5 V systems while supporting down-translation - inputs accept up to 5.5 V regardless of VCC level.

Functional behavior is defined by a three-mode state table: when OE = L, Y = A (true pass-through); when OE = H, Y = high-impedance (Z); and when OE is floating or undefined, output state is indeterminate. The device requires external pull-up on OE for power-up/down high-impedance safety.

Key Specifications

Pinout & Package

74AHC1G125DCKRE4 is housed in a 5-pin SC-70 (DCK) package measuring 2.00 mm × 2.1 mm (body: 2.0 mm × 1.25 mm), optimized for space-constrained PCB layouts and high-density routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHC1G125DCKR and 74LVC1G125GW,125, the 74AHC1G125DCKRE4 uniquely balances wide 2–5.5 V operation, 125°C rating, and ultra-low ICC - making it optimal for battery-backed industrial controllers and medical devices where voltage headroom and thermal margin are critical.

Availability

74AHC1G125DCKRE4 is available at Aetrix Electronics and suitable for TV backplane interfaces, projector timing control, and patient monitoring data buses requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74AHC1G125DCKRE4 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 interface ICs.

The SN74AHC1G125 product line delivers single-gate 3-state buffers for space-constrained, low-power digital interconnect - designed specifically for voltage translation, bus isolation, and mixed-signal system partitioning in medical, industrial, and consumer electronics.

FAQ

What is the maximum operating voltage for 74AHC1G125DCKRE4?

The 74AHC1G125DCKRE4 supports a supply voltage range of 2 V to 5.5 V. Its inputs tolerate up to 5.5 V regardless of VCC level, enabling safe interfacing with legacy 5 V logic even when powered from 3.3 V or 2.5 V rails. Absolute maximum VCC is 7 V, but sustained operation above 5.5 V violates recommended conditions and risks reliability degradation.

Does 74AHC1G125DCKRE4 support hot-swap or live-insertion?

The 74AHC1G125DCKRE4 does not include built-in hot-swap protection. However, its 3-state output and high-impedance off-state (IOZ ≤ ±2.5 µA) allow safe insertion into powered-backplane systems when OE is held high during insertion. External series resistors on A and Y lines are recommended to limit inrush current during plug-in events.

How should the OE pin be handled during power-up to ensure high-impedance startup?

To guarantee high-impedance output at power-up, OE must be tied to VCC via a pull-up resistor. TI recommends a value ≤10 kΩ to ensure OE reaches VIH (>3.85 V at VCC = 5.5 V) before VCC stabilizes. A 4.7 kΩ resistor is commonly used, providing sufficient current sinking capability while minimizing static power draw.

Can 74AHC1G125DCKRE4 drive a 50 Ω transmission line directly?

Yes - the 74AHC1G125DCKRE4 delivers ±8 mA output drive at 5 V, sufficient to source/sink into a 50 Ω load with ≤0.4 V VOL/VOH margin. For clean edges on longer traces, series termination (22–33 Ω) at the driver output is recommended to dampen reflections without compromising logic thresholds.

Is 74AHC1G125DCKRE4 pin-compatible with other SC-70 5-pin logic gates?

The 74AHC1G125DCKRE4 uses the standard SC-70-5 pinout (OE-A-GND-Y-VCC), matching TI's SN74AHC1Gxx family and compatible with industry-standard SC-70 footprints. However, function-specific pin assignments differ across logic types (e.g., inverters, AND gates), so direct substitution requires verification of truth table alignment and OE polarity.