onsemi MC74HCU04AFL2

Overview

MC74HCU04AFL2 from onsemi is a hex unbuffered inverter IC in high-performance silicon-gate CMOS technology, featuring six independent single-stage inverters with 2.0–6.0 V operating voltage, ±25 mA output drive per pin, and propagation delay as low as 12 ns at 6.0 V - used for oscillator circuits, pulse shaping, and logic-level translation in industrial timing and signal conditioning systems.

For engineers reviewing the MC74HCU04AFL2 datasheet, pinout, applications, or equivalent options, key selection considerations include its LSTTL-load compatibility (10 loads), high-input impedance, rail-to-rail input voltage range (0 to VCC), and dual-package availability in SOIC-14 and TSSOP-14 with Pb-free, RoHS-compliant construction.

Technical Context

The MC74HCU04AFL2 implements six identical unbuffered CMOS inverters with no internal stage buffering - enabling direct use in crystal oscillator configurations (2.5–6.0 V supply) and Schmitt-trigger-derived wave-shaping circuits. Its input structure supports both CMOS and LSTTL interfacing via external pullup resistors.

Each inverter exhibits symmetrical AC performance: tPLH/tPHL ≤ 18 ns at 4.5 V and ≤ 15 ns at 6.0 V (CL = 50 pF); output transition times (tTLH/tTHL) are ≤ 19 ns under same conditions. Input capacitance is guaranteed ≤ 10 pF, supporting high-frequency digital signal integrity without added loading.

Key Specifications

Pinout & Package

MC74HCU04AFL2 is available in TSSOP-14 (Case 948G) package - 4.9 mm × 4.4 mm body, 0.65 mm pitch, 1.2 mm max height - optimized for space-constrained PCB layouts while maintaining thermal derating of −6.1 mW/°C above 65°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCU04DR and 74HC04D,653, the MC74HCU04AFL2 offers broader temperature coverage (–55°C to +125°C), explicit AEC-Q100 qualification pathway via NLV variants, and tighter input leakage control (±1.0 µA vs. ±5.0 µA typical), making it preferred for mission-critical industrial timing and automotive subsystems.

Availability

MC74HCU04AFL2 is available at Aetrix Electronics and suitable for industrial control panels, automotive body electronics, test instrumentation, and embedded timing modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MC74HCU04AFL2 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, logic, and sensing solutions for automotive, industrial, cloud, and IoT applications.

The MC74HCU04AFL2 belongs to the HCU logic family - designed specifically for high-speed, low-power unbuffered inverter applications where minimal propagation delay, wide supply range, and robust noise immunity are essential in mixed-signal timing circuits.

FAQ

What is the maximum operating supply voltage for MC74HCU04AFL2?

The absolute maximum DC supply voltage (VCC) for MC74HCU04AFL2 is +7.0 V, but the recommended operating range is 2.0 V to 6.0 V. Operation above 6.0 V risks exceeding safe power dissipation limits and may degrade long-term reliability - always observe the 6.0 V upper limit in functional designs. The MC74HCU04AFL2 datasheet specifies guaranteed performance only within the 2.0–6.0 V band.

Can MC74HCU04AFL2 be used in crystal oscillator circuits?

Yes, MC74HCU04AFL2 is explicitly validated for crystal oscillator use in the manufacturer's datasheet (Figures 4 and 7), with recommended supply range 2.5–6.0 V. Its unbuffered architecture provides the necessary gain and phase characteristics for Pierce-type oscillators. External load capacitors and series resistor must be selected per crystal manufacturer guidelines to ensure startup and stability - the MC74HCU04AFL2 itself requires no additional configuration.

Does MC74HCU04AFL2 support LSTTL-level inputs without pull-up resistors?

No - MC74HCU04AFL2 inputs are CMOS-compatible and require VIH ≥ 1.7 V (at VCC = 2.0 V) to register a logic high. Standard LSTTL outputs swing only to ~3.4 V open-circuit and drop under load; therefore, external pull-up resistors to VCC are required for reliable interfacing. The MC74HCU04AFL2 datasheet confirms this in the "Features" section and recommends pullups for LSTTL compatibility.

What is the thermal derating specification for MC74HCU04AFL2 in TSSOP-14 package?

For the TSSOP-14 package (Case 948G), MC74HCU04AFL2 has a thermal derating factor of −6.1 mW/°C above 65°C ambient. Its maximum power dissipation in still air is 450 mW at ≤65°C, decreasing linearly to ~75 mW at +125°C. This derating must be applied when calculating total allowable power in high-temperature enclosures - the MC74HCU04AFL2 datasheet provides full derating curves in the "Maximum Ratings" section.

Is MC74HCU04AFL2 pin-compatible with older LS04 TTL inverters?

Yes - the MC74HCU04AFL2 has identical pinout to the 74LS04 and MC14069UB, as stated in the official datasheet. All six inverter inputs (pins 1,3,5,9,11,13) and outputs (pins 2,4,6,8,10,12) align exactly, with VCC on pin 14 and GND on pin 7. However, due to CMOS input structure, unused inputs must be tied to VCC or GND - unlike LS04, floating inputs on MC74HCU04AFL2 cause excessive current draw and instability.