STMicroelectronics 74ACT14MTR

Overview

74ACT14MTR from STMicroelectronics is a hex Schmitt-trigger inverter IC designed for noise-immune signal conditioning in high-speed digital interfaces. It features 7.2 ns typical propagation delay at 5V, ±24 mA symmetrical output drive, 0.4–1.5 V hysteresis, and operates across 2V–5.5V supply range-enabling robust reception of slow-rising TTL/CMOS signals in industrial control bus receivers.

For engineers reviewing the 74ACT14MTR datasheet, 74ACT14MTR pinout, 74ACT14MTR application, or 74ACT14MTR equivalent, key selection criteria include Schmitt input hysteresis width, transmission-line driving capability (50 Ω), ESD immunity (2 kV), and compatibility with legacy 74-series logic families under wide V_CC and temperature ranges (–55°C to +125°C).

Technical Context

The 74ACT14MTR implements six independent Schmitt-trigger inverters using sub-micron C2MOS technology, with three-stage buffered outputs ensuring stable switching and high noise immunity. Its input hysteresis (V_t+ = 2.0 V, V_t− = 0.6 V at V_CC = 4.5–5.5 V) enables reliable digitization of slow or noisy analog-like waveforms.

It delivers symmetrical ±24 mA output current into resistive loads and supports direct interfacing with TTL, NMOS, and CMOS systems. All I/O pins include integrated protection circuits providing 2 kV HBM ESD immunity and transient voltage tolerance without external clamping.

Key Specifications

Pinout & Package

74ACT14MTR is supplied in a 14-pin SOIC (Small Outline Integrated Circuit) package, 3.9 mm body width, with standard 1.27 mm pitch and gull-wing leads. Pin 1 marked by notch or bevel; pin 7 = GND, pin 14 = V_CC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHC14DR and MC74VHC14DT, the 74ACT14MTR provides superior noise rejection on marginal signals and guaranteed industrial-grade ESD robustness-making it the preferred choice where signal integrity and reliability outweigh minor cost or speed differences.

Availability

74ACT14MTR is available at Aetrix Electronics and suitable for industrial sensor interface, automotive body control, legacy system upgrade, and programmable logic glue applications requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for 74ACT14MTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, MCU, power, and discrete devices for industrial, automotive, and consumer markets.

The 74ACT14 belongs to ST's advanced high-speed CMOS logic family, engineered specifically for noise-immune signal conditioning and mixed-voltage interfacing in mission-critical embedded systems.

FAQ

Is 74ACT14MTR compatible with 5V TTL logic inputs?

Yes. The 74ACT14MTR accepts TTL-compatible input voltages (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V) and produces TTL-level outputs (V_OL ≤ 0.5 V, V_OH ≥ 3.7 V at 24 mA sink/source). Its Schmitt inputs further improve noise margin over standard TTL gates.

What is the maximum capacitive load this device can drive reliably?

The 74ACT14MTR is characterized for CL = 50 pF in AC specs, with guaranteed 7.2 ns propagation delay. While it can drive heavier loads, timing degradation occurs beyond 50 pF; for >100 pF, use series termination or buffer staging per STMicroelectronics AN1117 guidelines.

Does 74ACT14MTR require external pull-up or pull-down resistors on unused inputs?

No. Unused inputs must be tied to V_CC or GND to prevent floating states and excessive ICC. The internal Schmitt structure does not eliminate input bias requirements-floating inputs cause undefined output states and increased power consumption due to partial conduction.

Can 74ACT14MTR operate at 3.3V supply while maintaining full performance?

Yes. At V_CC = 3.3 V, it meets all AC/DC specs including hysteresis (V_t+ ≈ 1.7 V, V_t− ≈ 0.5 V), output drive (±24 mA), and propagation delay (≤11.4 ns max). Full functionality is guaranteed from 2.0 V to 5.5 V per Recommended Operating Conditions.