STMicroelectronics M74HC4078RM13TR

Overview

M74HC4078RM13TR from STMicroelectronics is a high-speed CMOS 8-input NOR/OR gate fabricated in silicon gate C2MOS technology, operating across 2V–6V supply, delivering 10ns typical propagation delay at 6V, ±4mA symmetrical output drive, and 1µA max quiescent current at 25°C - used in digital logic consolidation, address decoding, and bus arbitration circuits.

For engineers reviewing the M74HC4078RM13TR datasheet, M74HC4078RM13TR pinout, M74HC4078RM13TR application, or M74HC4078RM13TR equivalent, key selection criteria include input voltage thresholds (VIH/VIL), output drive capability under load (IOH/IOL), propagation delay symmetry (tPLH ≅ tPHL), noise immunity (28% VCC), and TSSOP-14 package compatibility with high-density PCB layouts.

Technical Context

This device integrates dual-function logic: an 8-input NOR gate and an 8-input OR gate sharing common inputs (pins 2–5, 9–12) and complementary outputs (Y on pin 1, X on pin 13). It uses C2MOS process for low static power and rail-to-rail switching, with input protection diodes against ESD and transient overvoltage.

Logic operation follows standard positive-logic conventions: Y = NOT(A+B+C+D+E+F+G+H), X = A+B+C+D+E+F+G+H. Propagation delays are balanced (tPLH ≅ tPHL), and output impedance is symmetrical (|IOH| = IOL ≥ 4mA), enabling predictable timing in combinational logic trees and enable/control signal generation.

Key Specifications

Pinout & Package

TSSOP-14 package: 4.9 × 6.4 mm body, 0.65 mm pitch, 1.2 mm height, lead-free, moisture sensitivity level 1 (MSL1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-input NOR/OR gate applications.

Compared with SN74HC4078DR and 74VHC4078FT, M74HC4078RM13TR uniquely supports full −55°C to +125°C operation in TSSOP-14 with MSL1 handling, making it the only option qualified for under-hood automotive and military-grade environmental stress.

Availability

M74HC4078RM13TR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, medical infusion pump logic, and automated test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for M74HC4078RM13TR 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 logic devices for industrial, automotive, and consumer markets.

M74HC4078 belongs to the high-speed HC logic family, engineered for low-power, high-noise-immunity digital interfacing in harsh environments - especially where legacy 74-series compatibility and extended temperature operation are mandatory.

FAQ

Is M74HC4078RM13TR pin-compatible with standard 74LS4078?

Yes - it is functionally and pin-compatible with 74LS4078 and 74F4078, sharing identical pinout (TSSOP-14), input/output logic behavior, and truth table. However, it operates at lower supply voltages (2–6V vs 4.75–5.25V), draws significantly less current, and offers higher noise immunity due to CMOS architecture.

Can both Y and X outputs be used simultaneously without contention?

Yes - Y (NOR) and X (OR) are fully independent, complementary outputs driven from the same input set. They do not share internal nodes or drive transistors, so simultaneous use introduces no contention, timing conflict, or increased power consumption beyond the sum of their individual loads.

What decoupling capacitance is recommended for stable 6V, 10MHz operation?

A minimum 100nF X7R ceramic capacitor placed ≤5mm from pins 14 (VCC) and 7 (GND) is required. For systems with fast-switching adjacent logic, add a 10nF capacitor in parallel. Layout must maintain low-inductance ground return paths to prevent VCC sag during output transitions.

Does M74HC4078RM13TR support partial power-down or I/O isolation when VCC = 0V?

No - it does not feature Ioff or power-down isolation. When VCC = 0V, inputs and outputs enter high-impedance states only if all inputs are held within −0.5V to VCC+0.5V (i.e., 0V ±0.5V). Applying signals to inputs or outputs while VCC is unpowered may cause leakage or latch-up; external isolation switches are required for hot-swap scenarios.