Texas Instruments CD74HC125QPWRG4Q1

Overview

CD74HC125QPWRG4Q1 from Texas Instruments is an AEC-Q100 Grade 1 qualified automotive quadruple buffer with 3-state outputs, operating from 2 V to 6 V supply, delivering propagation delay as low as 17 ns at 6 V and supporting fanout of up to 10 LSTTL loads in engine control units and body electronics.

For engineers reviewing the CD74HC125QPWRG4Q1 datasheet, CD74HC125QPWRG4Q1 pinout, CD74HC125QPWRG4Q1 application, or CD74HC125QPWRG4Q1 equivalent, key selection criteria include its -40°C to +125°C operating range, active-low 3-state enable architecture per channel, balanced CMOS output drive, and TSSOP-14 package compatibility with high-density automotive PCB layouts.

Technical Context

This device implements four independent non-inverting buffers (Y = A) with individually controlled active-low 3-state outputs, enabling selective signal routing in shared bus architectures. Each channel features standard CMOS inputs with input clamp diodes and balanced output stages capable of sourcing/sinking ±25 mA.

Its functional modes are defined by a three-state logic table: when OE is low, Y follows A; when OE is high, Y enters high-impedance state with off-state current ≤±10 µA. The design supports mixed-voltage interfacing across 2–6 V operation while maintaining rail-to-rail VOH/VOL performance.

Key Specifications

Pinout & Package

TSSOP-14 package (5.00 mm × 4.40 mm body size, 1.27 mm lead pitch), 1.75 mm max height, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC125APWR, CD74HC125QPWRG4Q1 provides wider voltage range and automotive qualification at the cost of speed; compared with CD74HC125M96G4Q1, it offers 18% smaller PCB area and improved thermal performance in space-constrained modules.

Availability

CD74HC125QPWRG4Q1 is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera interfaces, and electric power steering systems requiring stable component supply across automotive production lifecycles.

Supply support for CD74HC125QPWRG4Q1 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 company specializing in analog and embedded processing solutions, with leadership in automotive, industrial, and power management ICs.

The CD74HC125-Q1 product line delivers AEC-Q100 qualified HC-series logic for automotive signal routing, designed specifically to replace legacy TTL in harsh-environment control modules while maintaining pin compatibility and logic behavior.

FAQ

What is the maximum capacitive load the CD74HC125QPWRG4Q1 can drive while maintaining specified timing?

The CD74HC125QPWRG4Q1 is characterized for CL ≤50 pF in switching specifications, and TI recommends limiting total load capacitance to ≤70 pF for reliable operation. Exceeding this value increases propagation delay and transition time beyond datasheet limits - for example, at 6 V supply, tpd rises from 17 ns (CL = 50 pF) to >25 ns (CL = 100 pF). If higher capacitance is unavoidable, add a series resistor to limit peak output current per Absolute Maximum Ratings.

Does the CD74HC125QPWRG4Q1 support mixed-voltage operation between input and output sides?

No - the CD74HC125QPWRG4Q1 has a single VCC rail powering all inputs and outputs; it does not provide level-shifting capability. Input voltage must remain within 0 to VCC, and output swing is rail-to-rail (0 to VCC). For mixed-voltage interfacing, external level translators or discrete resistor dividers are required. The device's wide 2–6 V supply range does allow operation at intermediate voltages like 3.3 V or 5 V to bridge common logic families.

How should unused inputs and outputs be handled on the CD74HC125QPWRG4Q1?

Unused inputs must be terminated to VCC or GND using direct connection or a 10-kΩ pull-up/down resistor to prevent floating states that cause excessive current draw and logic instability. Unused outputs may be left floating, but must never be tied directly to VCC or GND - doing so violates Absolute Maximum Ratings and risks permanent damage. TI confirms this guidance applies identically across all four channels of the CD74HC125QPWRG4Q1.

What thermal derating applies to the CD74HC125QPWRG4Q1 in a 125°C ambient environment?

With RθJA = 151.7°C/W (TSSOP), the CD74HC125QPWRG4Q1 reaches its 150°C maximum junction temperature at just 16.5 mW of power dissipation at TA = 125°C. At typical ICC = 160 µA and VOH/VOL near rails, dynamic power dominates - Cpd = 29 pF/gate implies ~1.5 mW per channel at 10 MHz. Thus, full-speed operation across all four channels remains thermally safe even at max ambient, provided PCB copper area and airflow meet minimum layout guidelines.

Is the CD74HC125QPWRG4Q1 pin-compatible with non-automotive versions like CD74HC125M96G4?

Yes - the CD74HC125QPWRG4Q1 shares identical pin configuration, electrical behavior, and logic function with industrial-grade variants such as CD74HC125M96G4 and CD74HC125QPWRQ1. Differences are limited to qualification (AEC-Q100), marking, and packaging documentation; no circuit or layout changes are needed when substituting into existing designs meeting automotive reliability requirements.