onsemi MC74HCU04AFEL

Overview

MC74HCU04AFEL from onsemi is a hex unbuffered inverter IC in SOIC-14 package, operating from 2.0 V to 6.0 V, delivering 10 LSTTL load drive capability, <1 µA input leakage current, and propagation delay as low as 12 ns at 6.0 V - widely used in oscillator circuits, pulse shaping, and high-input-impedance amplification.

For engineers reviewing the MC74HCU04AFEL datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, SOIC-14 terminal mapping, JEDEC-compliant noise immunity data, and validated alternatives for digital logic design, clock generation, and interface conditioning.

Technical Context

The MC74HCU04AFEL implements six independent CMOS inverter stages with high-input impedance and rail-to-rail output swing. Its unbuffered architecture enables direct use in crystal and RC oscillator configurations, supporting stable oscillation across 2.5–6.0 V supply range.

Input compatibility spans standard CMOS outputs and LSTTL (with pullup resistors); output drive meets ±25 mA per pin with guaranteed VOH ≥ 5.5 V and VOL ≤ 0.5 V at 6.0 V/5.2 mA, satisfying mixed-logic interfacing requirements.

Key Specifications

Pinout & Package

MC74HCU04AFEL is housed in a Pb-free SOIC-14 (Case 751A) package, 8.75 mm × 3.90 mm × 1.75 mm, with standard 1.27 mm pitch and gull-wing leads suitable for reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCU04DR and 74HCU04D,653, the MC74HCU04AFEL uniquely combines AEC-Q100 qualification, −55°C to +125°C operation, and documented PPAP readiness - making it the only choice for Tier-1 automotive subsystems requiring zero-defect traceability and thermal resilience.

Availability

MC74HCU04AFEL is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, and medical diagnostic equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MC74HCU04AFEL 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, and cloud infrastructure markets.

The MC74HCU04AFEL belongs to the HCU logic family - designed specifically for high-speed, low-power unbuffered CMOS applications where oscillator stability, noise immunity, and wide supply voltage tolerance are critical.

FAQ

What is the maximum operating frequency achievable with MC74HCU04AFEL in an oscillator circuit?

The MC74HCU04AFEL supports stable crystal oscillator operation up to 10 MHz and RC-based oscillators exceeding 30 MHz depending on external component values and layout. Propagation delay as low as 12 ns at 6.0 V enables fast edge rates essential for high-frequency timing; however, actual frequency is determined by external crystal or RC network - not by the IC's internal speed limit alone. For optimal performance, keep trace lengths short and minimize stray capacitance near pins 1–12.

Does MC74HCU04AFEL require external pull-up resistors when interfacing with LSTTL devices?

Yes - the MC74HCU04AFEL inputs are compatible with LSTTL outputs only when external pull-up resistors are used, as stated in the datasheet. Without pull-ups, LSTTL's weak high-level output (typically ~3.4 V) may fall below the MC74HCU04AFEL's VIH threshold (e.g., 4.8 V at VCC = 6.0 V), causing unreliable logic high detection. A 10 kΩ pull-up to VCC ensures robust recognition of LSTTL logic highs across temperature and voltage variations.

Is MC74HCU04AFEL pin-compatible with the older MC14069UB hex inverter?

Yes - the MC74HCU04AFEL is explicitly stated in the datasheet to be identical in pinout to the MC14069UB. Both devices share the same 14-pin SOIC layout with inputs on odd-numbered pins (1,3,5,9,11,13), outputs on even-numbered pins (2,4,6,8,10,12), VCC on pin 14, and GND on pin 7. This allows drop-in replacement in legacy designs without PCB modification, provided voltage and timing requirements align.

Can MC74HCU04AFEL operate reliably at 2.0 V supply voltage?

Yes - the MC74HCU04AFEL is fully specified down to 2.0 V DC supply voltage, with guaranteed VOH ≥ 1.8 V and VOL ≤ 0.2 V under test conditions. At this minimum voltage, propagation delay increases to 70 ns (−55°C to 25°C), but functionality remains intact for low-power portable applications. Input thresholds scale proportionally, preserving noise margin, and quiescent current stays below 1 µA - ideal for coin-cell or energy-harvesting systems.

What does the "FEL" suffix indicate in MC74HCU04AFEL?

The "FEL" suffix in MC74HCU04AFEL denotes a specific packaging and compliance variant: "F" indicates tape-and-reel packaging, "E" signifies Pb-free construction, and "L" identifies the SOIC-14 package (Case 751A). This matches the ordering code MC74HCU04ADR2G in onsemi's documentation, confirming RoHS compliance, moisture sensitivity level 1, and standard industrial temperature grading (−55°C to +125°C).