Texas Instruments SN74AHC125QPWR

Overview

SN74AHC125QPWR from Texas Instruments is an automotive-grade quadruple bus buffer gate with independent 3-state outputs, operating from 2 V to 5.5 V supply, supporting −40°C to +125°C ambient temperature, and featuring EPIC™ CMOS process for latch-up immunity >250 mA per JESD17 - used in vehicle infotainment data routing and body control module signal isolation.

For engineers reviewing the SN74AHC125QPWR datasheet, SN74AHC125QPWR pinout, SN74AHC125QPWR application, or SN74AHC125QPWR equivalent, key selection criteria include 3-state output timing (tPLH/tPHL ≤ 6.5 ns at 5 V), rail-to-rail input voltage tolerance (0–5.5 V), low quiescent current (ICC ≤ 40 μA), and TSSOP-14 package compatibility with automotive PCB layout constraints.

Technical Context

This device implements four independent non-inverting buffers, each with dedicated active-low output-enable (OE) control. Each channel transitions between low-impedance pass-through mode (OE = low) and high-impedance tri-state mode (OE = high), enabling bidirectional bus sharing without contention.

Input thresholds scale with VCC (VIH = 0.7×VCC min, VIL = 0.3×VCC max), ensuring robust noise margin across 2 V–5.5 V operation. Output drive strength is specified at ±4 mA (3.3 V) and ±8 mA (5 V), with propagation delays measured under 15 pF load and defined transition rates (100 ns/V at 3.3 V).

Key Specifications

Pinout & Package

TSSOP-14 (PW) package: 5 mm × 6.4 mm body size, 1.2 mm max height, lead pitch 0.65 mm, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHC125QPWR, SN74LV125APW trades automotive qualification and lower static power for broader low-voltage support, while MC74VHC125DT offers minor speed gain at the cost of footprint compatibility and automotive compliance - making SN74AHC125QPWR the optimal choice for space-constrained, temperature-critical vehicle subsystems requiring guaranteed high-Z behavior.

Availability

SN74AHC125QPWR is available at Aetrix Electronics and suitable for automotive infotainment systems, body control modules, instrument clusters, and ADAS camera interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74AHC125QPWR 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 automotive electronics, with decades of automotive qualification expertise and broad portfolio coverage.

The SN74AHC125QPWR belongs to TI's AHC logic family designed specifically for high-speed, low-power, automotive-qualified digital interfacing - balancing speed, noise immunity, and thermal robustness for harsh-vehicle environments.

FAQ

What is the maximum clock/data rate supported by SN74AHC125QPWR?

The SN74AHC125QPWR supports reliable data transmission up to approximately 100 MHz, based on its worst-case propagation delay of 6.5 ns (at 5 V, 15 pF load) and rise/fall time specifications. This makes SN74AHC125QPWR suitable for high-speed parallel bus applications such as RGB display interfaces and sensor data multiplexing in automotive systems where timing margins must be preserved across temperature extremes.

Does SN74AHC125QPWR require external pull-up resistors on OE pins?

Yes - to ensure high-impedance outputs during power-up or brown-out conditions, SN74AHC125QPWR OE pins should be tied to VCC through a pull-up resistor. The minimum value depends on the driver's sink capability; TI recommends values between 10 kΩ and 100 kΩ. This prevents unintended output activation before system initialization completes, which is critical in automotive modules where undefined states could trigger false alarms or actuator movement.

Can SN74AHC125QPWR interface between 3.3 V and 5 V logic domains?

Yes - SN74AHC125QPWR supports mixed-voltage interfacing because its inputs tolerate 0–5.5 V regardless of VCC, and outputs swing rail-to-rail. When powered at 3.3 V, SN74AHC125QPWR can safely accept 5 V inputs and drive 3.3 V-compatible loads. However, driving 5 V-tolerant inputs from a 3.3 V-powered SN74AHC125QPWR requires verification that the receiving device recognizes 3.3 V as valid VIH - which most 5 V CMOS devices do (VIH ≥ 3.5 V). Always confirm with the downstream device's datasheet.

Is SN74AHC125QPWR pin-compatible with standard SN74AHC125 variants?

Yes - SN74AHC125QPWR shares identical pinout and functionality with non-automotive SN74AHC125 variants in TSSOP-14 (PW) package, including SN74AHC125PWR. The "Q" suffix denotes automotive qualification (AEC-Q100 Grade 1), but electrical characteristics, timing, and pin mapping are fully aligned. No PCB redesign is needed when upgrading from commercial to automotive grade within the same package.

What thermal derating applies to SN74AHC125QPWR in sealed automotive enclosures?

At TA = 125°C, SN74AHC125QPWR's RθJA is 113°C/W (TSSOP-14), meaning junction temperature rises ~113°C per watt dissipated. With typical ICC ≤ 40 μA and dynamic power Cpd × f × V² ≈ 0.5 mW at 10 MHz/5 V, self-heating remains negligible (<0.1°C). In sealed enclosures, thermal performance depends primarily on PCB copper area and airflow - TI recommends ≥1 cm² of 2-oz copper pour under the exposed pad (if present) and GND flood fill around the device to maintain TJ < 150°C under worst-case ambient.