STMicroelectronics M74HC08B1R

Overview

M74HC08B1R from STMicroelectronics is a high-speed CMOS quad 2-input AND gate in 14-pin DIP package, delivering 7 ns typical propagation delay at 6 V, ±4 mA symmetrical output drive, and operation across 2–6 V supply. It serves as a fundamental combinational logic element in digital control subsystems of industrial PLC I/O modules, where noise immunity (28% VCC) and rail-to-rail input/output compatibility ensure reliable signal gating under noisy 24 V DC field conditions.

For engineers reviewing the M74HC08B1R datasheet, M74HC08B1R pinout, M74HC08B1R application, or M74HC08B1R equivalent, key selection criteria include its guaranteed 4 mA output sink/source capability at 4.5 V, -55°C to +125°C extended temperature range, symmetrical tPLH/tPHL matching, low 1 µA max ICC quiescent current, and full pin/function compatibility with legacy 74LS08 logic families.

Technical Context

The M74HC08B1R implements four independent AND gates using silicon gate C2MOS technology, each with buffered output stages that enhance noise rejection and stabilize switching waveforms. Its internal structure ensures matched rise/fall times and balanced propagation delays across all channels.

It operates within a wide 2–6 V VCC range and supports TTL- and CMOS-level inputs simultaneously due to its wide VIH/VIL thresholds (e.g., VIH = 3.15 V min at 4.5 V VCC). Input protection diodes and ESD-hardened design enable robustness in industrial environments without external clamping.

Key Specifications

Pinout & Package

Package: Plastic Dual In-line Package (DIP-14), 0.3" wide, through-hole mountable with 2.54 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 2-input AND gate applications.

Compared with SN74HC08N and 74VHC08N, the M74HC08B1R uniquely combines extended temperature support, lowest quiescent current, and highest noise immunity-making it optimal for safety-critical or thermally demanding embedded control.

Availability

M74HC08B1R is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, medical diagnostic instrumentation, and test equipment requiring stable component supply over long production lifecycles.

Supply support for M74HC08B1R 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, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The M74HC08B1R belongs to ST's high-speed HC logic family, engineered specifically for drop-in replacement of 74LS devices while delivering CMOS power efficiency and enhanced noise resilience in harsh environments.

FAQ

Is M74HC08B1R pin-compatible with 74LS08?

Yes, M74HC08B1R is fully pin- and function-compatible with 74LS08, including identical DIP-14 pinout and truth table. However, it requires no pull-up resistors on inputs and draws significantly less supply current-enabling direct substitution in existing LS-based designs with improved noise margin and wider VCC range.

What decoupling capacitance is recommended for M74HC08B1R?

A 100 nF X7R ceramic capacitor placed within 5 mm of the VCC (pin 14) and GND (pin 7) pins is required. For systems with high-frequency switching or shared power rails, add a 10 µF tantalum or aluminum polymer capacitor per 5–10 ICs to suppress low-frequency supply droop.

Can M74HC08B1R drive LED indicators directly?

No-its absolute maximum output current is ±25 mA, but sustained 4 mA drive is specified only at VOH/VOL limits. Driving LEDs requires series current-limiting resistors (e.g., 1 kΩ for ~4 mA at 5 V) and must avoid simultaneous sourcing/sinking across multiple outputs to prevent exceeding total package power dissipation (500 mW at 65°C).

Does M74HC08B1R support mixed-voltage interfacing (e.g., 3.3 V MCU to 5 V peripheral)?

Yes-the input thresholds scale with VCC (VIH = 3.15 V min at 4.5 V), so a 3.3 V MCU output meets VIH requirement when M74HC08B1R runs at 5 V. However, its outputs swing rail-to-rail, so direct connection to 3.3 V-only inputs requires a level-shifting resistor divider or buffer to avoid overvoltage damage.