onsemi MC74ACT14MELG

Overview

MC74ACT14MELG from onsemi is a hex Schmitt-trigger inverter IC designed for signal conditioning and noise-immune digital interface applications. It features TTL-compatible inputs, 24 mA output drive capability, 1.2 V typical hysteresis at 5 V supply, propagation delay ≤12.5 ns (tPLH/tPHL), and operates across −40°C to +85°C. It is used in clock shaping, debouncing mechanical switches, and cleaning up slow-rising sensor signals.

For engineers reviewing the MC74ACT14MELG datasheet, pinout, applications, or equivalent options, this page delivers verified functional identity, SOIC-14 package mapping, six-channel Schmitt inverter behavior, input threshold asymmetry, and direct alternatives with documented electrical and application differences.

Technical Context

The MC74ACT14MELG implements six independent CMOS inverters with internal hysteresis-positive-going threshold ~2.0 V and negative-going threshold ~0.8 V at VCC = 5.0 V-enabling robust noise rejection on noisy input lines. Its TTL-compatible input structure accepts VIH ≥ 2.0 V and VIL ≤ 0.8 V, while delivering full CMOS output swing (VOH ≥ 4.4 V, VOL ≤ 0.44 V at IOL/IOH = ±24 mA).

It operates within a strict 4.5 V to 5.5 V supply range per Recommended Operating Conditions, supports 50 pF capacitive loads, and exhibits low dynamic power dissipation (CPD = 25 pF) with ICC ≤ 40 µA in quiescent state. Input capacitance is 4.5 pF, and propagation delays are characterized at both 25°C and −40°C to +85°C ambient.

Key Specifications

Pinout & Package

MC74ACT14MELG is supplied in a 14-lead SOIC (Small Outline Integrated Circuit) package, case 751A, with standard 1.27 mm pitch and Pb-free finish. Dimensions: 8.55–8.75 mm × 3.80–4.00 mm × 1.35–1.75 mm height.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV14APWR and 74HC14D,653, the MC74ACT14MELG uniquely delivers TTL-compatible inputs plus ±24 mA drive in a single SOIC-14 package-making it optimal for upgrading legacy 5 V systems requiring robust noise immunity and load-driving capability without voltage translation.

Availability

MC74ACT14MELG is available at Aetrix Electronics and suitable for industrial sensor interfaces, microcontroller input conditioning, digital clock shaping, and legacy bus signal restoration requiring stable component supply and long-term industrial availability.

Supply support for MC74ACT14MELG 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 focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.

The MC74ACT14MELG belongs to onsemi's legacy 74ACT logic family, engineered specifically for high-noise industrial and automotive-adjacent environments where TTL compatibility, strong output drive, and precise Schmitt thresholds are required.

FAQ

What is the supply voltage range for MC74ACT14MELG?

The MC74ACT14MELG operates strictly within 4.5 V to 5.5 V, as defined in its Recommended Operating Conditions. Operation outside this range-especially below 4.5 V-may result in unreliable TTL input recognition or degraded hysteresis performance. This narrow window ensures consistent noise margin and output drive strength, and is distinct from broader-range variants like the 74AC14 or 74HC14. Always verify VCC stability within this band in your design.

Does MC74ACT14MELG support true TTL input levels?

Yes, MC74ACT14MELG explicitly supports TTL-compatible inputs: VIH ≥ 2.0 V and VIL ≤ 0.8 V at VCC = 5.0 V. This allows direct connection to 74LS, 74F, and older microcontroller outputs without level-shifting circuitry. Unlike CMOS-input variants (e.g., 74HC14), the MC74ACT14MELG guarantees correct logic interpretation of standard TTL voltage thresholds across its full temperature range.

What is the typical hysteresis voltage of MC74ACT14MELG at 5 V supply?

The MC74ACT14MELG provides a typical hysteresis voltage of 1.2 V at VCC = 5.0 V, calculated as the difference between positive-going (Vt+ ≈ 2.0 V) and negative-going (Vt− ≈ 0.8 V) input thresholds. This value is internally set by transistor ratios and remains stable across temperature and supply variation-critical for eliminating chatter in mechanical switch or slow-rising sensor applications.

Can MC74ACT14MELG drive an LED directly?

Yes, MC74ACT14MELG can drive a standard 2 mA–10 mA indicator LED directly using its 24 mA sink capability (IOL = 24 mA). Configure the LED anode to VCC and cathode to an output pin (e.g., pin 2), enabling active-low illumination. Ensure series resistance limits current to ≤24 mA and respects VOL ≤ 0.44 V at full load. Avoid sustained maximum-current operation to maintain thermal reliability.

Is MC74ACT14MELG pin-compatible with other 74xx14 variants?

MC74ACT14MELG shares the standard 14-pin SOIC layout and identical pinout (inputs on odd pins 1/3/5/9/11/13, outputs on even pins 2/4/6/8/10/12, VCC on 14, GND on 7) with industry-standard hex Schmitt inverters including 74HC14, 74AC14, and SN74LV14A. However, electrical behavior-including input thresholds, drive strength, and supply range-differs significantly; verify logic compatibility and loading before substitution.