onsemi MC74VHCT02ADT

Overview

MC74VHCT02ADT from ON Semiconductor is a quad 2-input NOR gate IC in TSSOP-14 package, operating at 4.5–5.5 V, delivering 3.6 ns typical propagation delay and 2 μA max quiescent current. It features TTL-compatible inputs (VIH = 2.0 V, VIL = 0.8 V), 5 V CMOS-level outputs, and robust input/output protection up to 7 V - used in level-shifting logic interfaces between 3.3 V and 5 V systems.

For engineers reviewing the MC74VHCT02ADT datasheet, pinout, applications, or equivalent options, key selection criteria include propagation delay vs. supply voltage, input tolerance for mixed-voltage interfacing, output drive capability (±8 mA), latchup immunity (>300 mA), and Pb-free TSSOP packaging compliance.

Technical Context

This device implements four independent 2-input NOR gates using silicon-gate CMOS technology, achieving bipolar-Schottky TTL speed while retaining CMOS power efficiency. Its three-stage internal architecture includes a buffered output stage that enhances noise immunity and stabilizes switching behavior under capacitive loads.

The VHCT input structure tolerates voltages from –0.5 V to +7.0 V regardless of VCC, enabling safe hot-insertion and battery-backup operation; output structures remain protected even when VCC = 0 V. Input thresholds are fixed at VIH = 2.0 V and VIL = 0.8 V, ensuring reliable TTL-level recognition across temperature (–40°C to +85°C).

Key Specifications

Pinout & Package

MC74VHCT02ADT is housed in a 14-lead Thin Shrink Small Outline Package (TSSOP), case 948G−01, with 0.65 mm pitch, 4.9–5.1 mm width, and 6.4 mm length - optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NOR gate applications.

Compared with SN74LVC02APW and 74HC02D, the MC74VHCT02ADT uniquely combines 5 V system compatibility, fixed TTL input thresholds, sub-4 ns speed, and 7 V input tolerance - making it irreplaceable in legacy-to-modern voltage interface applications without circuit rework.

Availability

MC74VHCT02ADT is available at Aetrix Electronics and suitable for industrial control logic, automotive body electronics, legacy interface adapters, and medical diagnostic instruments requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MC74VHCT02ADT 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

ON Semiconductor (now part of onsemi) is a global semiconductor supplier specializing in energy-efficient power, analog, sensing, and logic solutions for automotive, industrial, and cloud infrastructure markets.

The MC74VHCT02ADT belongs to the VHCT logic family, engineered to bridge TTL and CMOS domains with speed, low power, and robust voltage-level interoperability - targeting mixed-voltage system integration.

FAQ

What is the maximum input voltage the MC74VHCT02ADT can safely tolerate?

The MC74VHCT02ADT supports DC input voltages from –0.5 V to +7.0 V, independent of VCC level. This allows direct connection to 3 V, 5 V, or transient-overvoltage nodes without external clamping - critical for hot-swap and battery-backup applications where supply sequencing is uncontrolled. The input protection structure remains functional even when VCC = 0 V.

Does the MC74VHCT02ADT support 3.3 V logic inputs while powered from 5 V?

Yes - the MC74VHCT02ADT has TTL-compatible inputs with fixed VIH = 2.0 V and VIL = 0.8 V, so 3.3 V logic signals meet the high-level threshold with margin. When powered at 5 V, it delivers full 5 V CMOS output swings, enabling clean level translation from 3.3 V controllers to 5 V peripherals without additional level shifters.

What is the recommended operating temperature range for the MC74VHCT02ADT?

The MC74VHCT02ADT is specified for continuous operation from –40°C to +85°C ambient temperature. All key parameters - including propagation delay (3.6 ns typ), output drive (±8 mA), and input thresholds - are guaranteed across this range per the manufacturer's recommended operating conditions, making it suitable for under-hood automotive and industrial environments.

Can unused inputs on the MC74VHCT02ADT be left floating?

No - unused inputs on the MC74VHCT02ADT must be tied to a valid logic level (VCC or GND) to prevent undefined output states, increased power consumption, and potential oscillation. Floating inputs may drift into the linear region due to leakage or noise, causing excessive shoot-through current and thermal stress in the output stage.

Is the MC74VHCT02ADT pin-compatible with standard 74-series NOR gates?

Yes - the MC74VHCT02ADT is functionally and pin-compatible with industry-standard 74xx02 devices (e.g., 74LS02, 74HC02) in the same 14-pin TSSOP package. Its pin assignment matches the standard dual-in-line layout: inputs A1/B1–A4/B4 and outputs Y1–Y4 align identically, enabling drop-in replacement in existing designs without PCB modification.