Nexperia USA Inc. 74AHCT125BQ,115

Overview

74AHCT125BQ,115 from Nexperia is a quad 3-state buffer/line driver with TTL-compatible inputs, operating from 4.5 V to 5.5 V supply, featuring overvoltage-tolerant inputs up to 5.5 V, propagation delay ≤7.0 ns (VCC = 5 V, CL = 15 pF), and guaranteed operation from –40 °C to +125 °C in DHVQFN14 (SOT762-1) package. It serves as a level-translating bus driver in mixed-voltage digital systems such as industrial I/O expansion and microcontroller peripheral interfacing.

For engineers reviewing the 74AHCT125BQ,115 datasheet, 74AHCT125BQ,115 pinout, 74AHCT125BQ,115 application, or 74AHCT125BQ,115 equivalent, this page delivers verified functional identity, validated thermal-enhanced QFN pin mapping, confirmed TTL-input logic thresholds, real-world timing specs under load, and cross-referenced alternatives for bus buffering and voltage translation use cases.

Technical Context

The 74AHCT125BQ,115 implements four independent non-inverting buffers, each with active-low 3-state output enable (nOE). Its TTL-level input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 4.5–5.5 V) ensure compatibility with legacy 5 V TTL logic while driving CMOS loads. The device uses standard CMOS silicon with Schmitt-trigger action on all inputs for noise immunity.

Each buffer supports bidirectional voltage translation via overvoltage-tolerant inputs (up to 5.5 V regardless of VCC), enabling safe interfacing between 3.3 V controllers and 5 V peripherals. Output drive strength is ±8 mA at VCC = 4.5 V, with balanced tPLH/tPHL propagation delays and defined enable/disable timing (ten ≤9.5 ns, tdis ≤11.0 ns at VCC = 5 V, CL = 50 pF).

Key Specifications

Pinout & Package

DHVQFN14 (SOT762-1) package: 2.5 mm × 3.0 mm × 0.85 mm body, 0.5 mm pitch, exposed thermal pad (non-soldered by default), 14 terminals, no leads. Pin 1 index area marked on top surface.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 3-state buffer applications.

Compared with 74AHCT125PW,118 and SN74AHCT125DR, the 74AHCT125BQ,115 offers superior thermal performance in space-constrained layouts and broader industrial temperature validation, making it the preferred choice for high-reliability embedded systems where thermal headroom and ambient range are critical.

Availability

74AHCT125BQ,115 is available at Aetrix Electronics and suitable for industrial I/O expansion, microcontroller peripheral interface, legacy system bus interface, and programmable logic interconnect requiring stable component supply across extended temperature ranges.

Supply support for 74AHCT125BQ,115 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

Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74AHCT125BQ,115 belongs to Nexperia's industry-standard logic family designed specifically for robust, low-power, mixed-voltage digital interfacing in harsh industrial environments.

FAQ

Is the 74AHCT125BQ,115 pin-compatible with the 74AHC125BQ,115?

Yes - both share identical pinout, package (SOT762-1), and functional topology. The key difference lies in input threshold compatibility: 74AHCT125BQ,115 accepts TTL-level inputs (VIH ≥ 2.0 V), whereas 74AHC125BQ,115 requires CMOS-level inputs (VIH ≥ 3.85 V at VCC = 5.5 V). Swapping them requires verifying source logic family voltage levels.

Can the exposed thermal pad on the DHVQFN package be soldered to ground?

The exposed pad (pin 1 index area) has no electrical requirement to be soldered. If connected, it must remain floating or tied to GND - never to VCC or any other voltage. Soldering improves thermal performance but requires controlled reflow profile to avoid voiding; Nexperia recommends keeping the land unconnected unless thermal simulation confirms benefit.

What is the maximum capacitive load the 74AHCT125BQ,115 can drive while maintaining timing specs?

Timing specifications (tpd, ten, tdis) are guaranteed up to 50 pF load capacitance per output, as tested per Figure 6 in the datasheet. Driving >50 pF increases propagation delay nonlinearly and may violate setup/hold margins; for >100 pF loads, consider adding series termination or using a dedicated line driver with higher current capability.

Does the 74AHCT125BQ,115 support hot insertion or live bus connection?

No - the device lacks powered-off protection (Ioff) or bus-hold circuitry. Connecting or disconnecting while powered risks latch-up or ESD damage due to uncontrolled voltage sequencing. Use external series resistors or dedicated hot-swap controllers if live insertion is required in the system architecture.