NXP Semiconductors 74HCT14D/AUJ

Overview

74HCT14D/AUJ from Nexperia is a hex inverting Schmitt trigger IC designed for noise-immune signal conditioning in digital logic interfaces. It features TTL-compatible input thresholds (VT+ = 1.41 V, VT− = 0.85 V at VCC = 4.5 V), 6 independent channels, and operates from 4.5 V to 5.5 V across −40 °C to +125 °C. It is used in waveform shaping circuits where slow-rising signals require clean digital edge regeneration.

For engineers reviewing the 74HCT14D/AUJ datasheet, 74HCT14D/AUJ pinout, 74HCT14D/AUJ application, or 74HCT14D/AUJ equivalent, this device delivers deterministic hysteresis-based noise rejection, sub-34 ns propagation delay at 4.5 V, and robust ESD protection (HBM >2000 V) - critical for industrial control inputs, sensor interface debouncing, and clockless oscillator design.

Technical Context

The 74HCT14D/AUJ implements six independent CMOS Schmitt-trigger inverters with asymmetric input threshold levels optimized for TTL-level compatibility. Its VT+ (1.41 V) and VT− (0.85 V) at 4.5 V yield 0.56 V hysteresis, enabling reliable rejection of noise up to ±280 mV on slow-transitioning signals.

Each channel drives ±4.0 mA at VCC = 4.5 V with VOL ≤ 0.26 V and VOH ≥ 3.98 V, supporting direct interfacing to 74-series TTL and CMOS loads. Input clamp diodes allow safe operation with input voltages exceeding VCC when current-limited.

Key Specifications

Pinout & Package

74HCT14D/AUJ uses the SO14 (SOT108-1) plastic small outline package: 14-pin, 3.9 mm body width, 1.27 mm pitch, gull-wing leads. Thermal resistance θJA = 100 K/W (JEDEC Std. 51-2).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Schmitt-trigger inverter applications.

Compared with SN74HCT14DR and MC74HCT14ADTR2G, the 74HCT14D/AUJ uniquely combines full automotive-grade temperature range (−40 °C to +125 °C), industry-leading latch-up immunity (100 mA), and JEDEC-compliant SO14 packaging - making it the preferred choice for high-reliability industrial control and power electronics monitoring where thermal margin and transient robustness are critical.

Availability

74HCT14D/AUJ is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and consumer appliance control systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HCT14D/AUJ 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 high-volume, high-reliability logic, discrete, and MOSFET solutions, serving automotive, industrial, and consumer markets with ISO/TS 16949-certified manufacturing.

The 74HCT14D/AUJ belongs to Nexperia's 74HCT logic family, engineered specifically for TTL-compatible interfacing in noise-prone environments - emphasizing robustness, wide temperature operation, and drop-in replaceability in legacy 5 V digital systems.

FAQ

What is the maximum operating supply voltage for the 74HCT14D/AUJ?

The 74HCT14D/AUJ has an absolute maximum supply voltage (VCC) of +7.0 V, but its recommended operating range is strictly 4.5 V to 5.5 V per JEDEC JESD7A compliance. Operating outside this window risks violating TTL input threshold alignment and may degrade noise immunity or increase ICC beyond specification. Always maintain VCC within 4.5–5.5 V for guaranteed 74HCT14D/AUJ functionality.

Does the 74HCT14D/AUJ support operation at −40 °C to +125 °C?

Yes, the 74HCT14D/AUJ is fully specified and tested across −40 °C to +125 °C ambient temperature, as confirmed in Table 5 (Recommended operating conditions) and Table 6 (Static characteristics) of the Nexperia datasheet Rev. 10. This makes the 74HCT14D/AUJ suitable for engine control units, industrial motor drives, and outdoor infrastructure where extreme thermal cycling occurs.

How does the hysteresis of the 74HCT14D/AUJ improve noise immunity?

The 74HCT14D/AUJ provides 0.56 V typical hysteresis (VH = VT+ − VT− = 1.41 V − 0.85 V at VCC = 4.5 V), creating a voltage dead-band that prevents multiple output transitions when input signals hover near the switching threshold. This directly suppresses noise-induced glitches from EMI, crosstalk, or mechanical switch bounce - a key advantage over standard inverters in the 74HCT14D/AUJ's target applications.

Can the 74HCT14D/AUJ inputs tolerate voltages above VCC?

Yes, the 74HCT14D/AUJ includes integrated input clamp diodes to VCC and GND. When driven with voltages up to VCC + 0.5 V, the diode conducts - provided external current limiting (e.g., ≥1 kΩ series resistor) keeps IIK within ±20 mA (Table 4). This allows safe interfacing with 12 V sensors or open-collector signals without external protection, a verified feature of the 74HCT14D/AUJ.

What is the typical propagation delay of the 74HCT14D/AUJ at 5 V supply?

At VCC = 5.0 V with CL = 15 pF, the 74HCT14D/AUJ exhibits a typical propagation delay (tpd) of 17 ns, with a maximum of 34 ns across −40 °C to +125 °C (Table 7). This delay is measured between 50 % input and 50 % output thresholds and remains stable across temperature - critical for predictable timing in relaxation oscillators and synchronous debounce circuits using the 74HCT14D/AUJ.