onsemi MC74VHCT32ADR2

Overview

MC74VHCT32ADR2 from onsemi is a quad 2-input OR gate with TTL-compatible inputs and full 5.0 V CMOS output swing, designed for logic-level translation between 1.8 V/3.0 V and 5.0 V systems. It operates from 2.0 V to 5.5 V, delivers 3.8 ns typical propagation delay at 5.0 V, supports ±25 mA output drive, and features input overvoltage tolerance up to 7.0 V - enabling safe interfacing of mixed-voltage digital subsystems.

For engineers reviewing the MC74VHCT32ADR2 datasheet, pinout, applications, or equivalent options, key selection criteria include its LSTTL-compatible input thresholds (VIL = 0.8 V, VIH = 2.0 V), rail-to-rail 5.0 V output swing, 3.8 ns tPD at 5 V/50 pF, input overvoltage protection, and SOIC-14 package compatibility with legacy 74-series logic layouts.

Technical Context

The MC74VHCT32ADR2 implements four independent 2-input OR gates using silicon-gate CMOS technology, achieving bipolar-Schottky TTL speed while retaining CMOS power efficiency. Its three-stage internal structure includes a buffered output stage that ensures high noise immunity and stable switching behavior across temperature and load variations.

Input circuitry incorporates robust protection diodes allowing safe operation with input voltages up to 7.0 V regardless of VCC, supporting hot-insertion and supply-mismatch scenarios. Output structures remain protected even when VCC = 0 V, preventing latch-up or damage during power sequencing in mixed-supply systems.

Key Specifications

Pinout & Package

MC74VHCT32ADR2 is housed in a 14-pin SOIC package (Case 751A, D suffix), with standard 1.27 mm pitch and 8.65 mm × 3.91 mm footprint compatible with automated assembly and legacy PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar OR gate logic-level translation applications.

Compared with SN74VHCT32DR and 74LCX32MTCX, the MC74VHCT32ADR2 uniquely supports 5.0 V operation with 7.0 V input tolerance and sub-4 ns propagation - making it the only choice for retrofitting 5 V legacy systems with modern low-voltage logic while maintaining timing integrity and robustness.

Availability

MC74VHCT32ADR2 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, and legacy 5 V system modernization requiring stable component supply and long-term lifecycle support.

Supply support for MC74VHCT32ADR2 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 manufacturer specializing in energy-efficient power management, analog, logic, and sensing solutions for automotive, industrial, and medical applications.

The VHCT logic family - including the MC74VHCT32ADR2 - was engineered specifically for seamless integration between legacy TTL/CMOS systems and modern low-voltage logic, emphasizing voltage translation, robustness, and drop-in replaceability in industrial control and automotive electronics.

FAQ

What is the maximum supply voltage rating for MC74VHCT32ADR2?

The MC74VHCT32ADR2 has an absolute maximum DC supply voltage (VCC) rating of +7.0 V, though recommended operating range is 2.0 V to 5.5 V. This 7.0 V rating applies to both VCC and input pins, enabling safe operation during transient overvoltage events such as load dump or ESD coupling. The MC74VHCT32ADR2 maintains functionality and avoids damage even when inputs exceed VCC by up to 2.0 V.

Can MC74VHCT32ADR2 be used to translate 1.8 V logic to 5.0 V?

Yes, the MC74VHCT32ADR2 supports 1.8 V CMOS logic inputs when operated at VCC = 5.0 V. Its TTL-compatible input thresholds (VIH = 2.0 V max, VIL = 0.8 V max) ensure reliable recognition of 1.8 V logic HIGH (typically >1.35 V) and LOW (<0.45 V). The MC74VHCT32ADR2 then produces full 5.0 V CMOS output swing, making it suitable for translating 1.8 V FPGA I/O to 5 V peripherals without external components.

Is MC74VHCT32ADR2 pin-compatible with standard 74LS32?

Yes, the MC74VHCT32ADR2 uses the same SOIC-14 pinout and logic function as the 74LS32, with identical pin assignments for all four OR gates, VCC, and GND. It is functionally and physically pin-compatible, allowing direct replacement in existing 74LS32 layouts. The MC74VHCT32ADR2 improves upon the LS32 with lower power consumption, higher noise immunity, and input overvoltage tolerance - all while maintaining the same timing envelope.

Does MC74VHCT32ADR2 require external pull-up or pull-down resistors on unused inputs?

Yes, unused inputs on the MC74VHCT32ADR2 must be tied to a defined logic level - either VCC or GND - to prevent floating nodes that could cause excessive current draw, oscillation, or increased EMI. The datasheet explicitly states that unused inputs must not be left open. This requirement applies to all four OR gates; leaving any A or B input unconnected risks unpredictable output behavior and violates the device's recommended operating conditions.

What is the thermal derating specification for MC74VHCT32ADR2 in SOIC package?

The MC74VHCT32ADR2 in SOIC-14 package (Case 751A) has a thermal derating factor of −7 mW/°C above 65°C ambient temperature. At 125°C maximum operating temperature, its power dissipation capability drops from 500 mW (at ≤65°C) to approximately 458 mW. This derating ensures safe junction temperature operation under sustained load and must be accounted for in high-density or high-temperature industrial designs using the MC74VHCT32ADR2.